Document And Entity Information - shares	9 Months Ended
Document And Entity Information - shares	Sep. 30, 2019	Oct. 31, 2019
Document Information [Line Items]
Entity Registrant Name	Dorchester Minerals, L.P.
Entity Central Index Key	0001172358
Trading Symbol	dmlp
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Current Reporting Status	Yes
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Common Stock, Shares Outstanding (in shares)		34,679,774
Entity Shell Company	false
Document Type	10-Q
Document Period End Date	Sep. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false
Title of 12(b) Security	Common stock

Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 21,916	$ 18,285
Trade and other receivables	6,323	6,635
Net profits interests receivable - related party	3,664	5,198
Total current assets	31,903	30,118
Property and leasehold improvements - at cost:
Oil and natural gas properties (full cost method)	405,641	363,205
Accumulated full cost depletion	(316,131)	(306,335)
Total	89,510	56,870
Operating lease right-of-use asset	1,695
Total assets	123,974	87,923
Current liabilities:
Accounts payable and other current liabilities	3,461	421
Operating lease liability	309
Deferred rent incentive		65
Total current liabilities	3,770	486
Operating lease liability	2,261
Deferred rent incentive		790
Total liabilities	6,031	1,276
Partnership capital:
General partner	1,482	1,826
Unitholders	116,461	84,821
Total partnership capital	117,943	86,647
Total liabilities and partnership capital	123,974	87,923
Leasehold Improvements [Member]
Property and leasehold improvements - at cost:
Leasehold improvements	989	1,614
Accumulated amortization	(123)	(679)
Total	$ 866	$ 935

Condensed Consolidated Income Statements (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Net operating revenues:
Operating revenues	$ 19,569	$ 13,938	$ 59,200	$ 50,944
Costs and expenses:
Operating, including production taxes	1,380	1,396	4,781	3,968
Depreciation, depletion and amortization	3,628	2,396	9,865	6,864
General and administrative expenses	1,694	867	4,112	3,506
Total costs and expenses	6,702	4,659	18,758	14,338
Net income	12,867	9,279	40,442	36,606
Allocation of net income:
General partner	463	361	1,364	1,311
Unitholders	$ 12,404	$ 8,918	$ 39,078	$ 35,295
Net income per common unit (basic and diluted) (in dollars per share)	$ 0.35	$ 0.27	$ 1.15	$ 1.09
Weighted average basic and diluted common units outstanding (in shares)	34,680	32,280	33,960	32,280
Royalty [Member]
Net operating revenues:
Operating revenues	$ 14,075	$ 12,889	$ 44,629	$ 40,076
Net Profit Interests [Member]
Net operating revenues:
Operating revenues	2,259	430	10,523	5,989
Lease Bonus [Member]
Net operating revenues:
Operating revenues	3,147	306	3,569	4,469
Product and Service, Other [Member]
Net operating revenues:
Operating revenues	$ 88	$ 313	$ 479	$ 410

Condensed Consolidated Statements of Changes in Partnership Capital (Unaudited) - USD ($) $ in Thousands	General Partner [Member]	Limited Partner [Member]	Total
Balance at Dec. 31, 2017	$ 1,782	$ 88,964	$ 90,746
Balance (in shares) at Dec. 31, 2017			32,279,774
Net income	1,311	35,295	$ 36,606
Distributions	(1,403)	(43,340)	(44,743)
Balance at Sep. 30, 2018	1,690	80,919	$ 82,609
Balance (in shares) at Sep. 30, 2018			32,279,774
Balance at Jun. 30, 2018	1,839	89,344	$ 91,183
Balance (in shares) at Jun. 30, 2018			32,279,774
Net income	361	8,918	$ 9,279
Distributions	(510)	(17,343)	(17,853)
Balance at Sep. 30, 2018	1,690	80,919	$ 82,609
Balance (in shares) at Sep. 30, 2018			32,279,774
Balance at Dec. 31, 2018	1,826	84,821	$ 86,647
Balance (in shares) at Dec. 31, 2018			32,279,774
Net income	1,364	39,078	$ 40,442
Distributions	(1,708)	(51,262)	(52,970)
Acquisition of assets for units		43,824	$ 43,824
Acquisition of assets for units (in shares)			2,400,000
Balance at Sep. 30, 2019	1,482	116,461	$ 117,943
Balance (in shares) at Sep. 30, 2019			34,679,774
Balance at Jun. 30, 2019	1,611	121,918	$ 123,529
Balance (in shares) at Jun. 30, 2019			34,679,774
Net income	463	12,404	$ 12,867
Distributions	(592)	(17,861)	(18,453)
Balance at Sep. 30, 2019	$ 1,482	$ 116,461	$ 117,943
Balance (in shares) at Sep. 30, 2019			34,679,774

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Net cash provided by operating activities	$ 54,756	$ 46,685
Cash flows provided by (used in) investing activities:
Cash contributed (used) in acquisitions	1,406	(25)
Capital expenditures		(41)
Proceeds from the sale of oil and natural gas properties	439
Total cash flows provided by (used in) investing activities	1,845	(66)
Cash flows used in financing activities:
Distributions paid to general partner and unitholders	(52,970)	(44,743)
Increase in cash and cash equivalents	3,631	1,876
Cash and cash equivalents at beginning of period	18,285	13,827
Cash and cash equivalents at end of period	21,916	15,703
Non-cash investing and financing activities:
Fair value of common units issued for acquisitions	$ 43,824

Note 1 - Basis of Presentation	9 Months Ended
Note 1 - Basis of Presentation	Sep. 30, 2019
Notes to Financial Statements
Basis of Presentation and Significant Accounting Policies [Text Block]	1 Basis of Presentation: Dorchester Minerals, L.P. (the “Partnership”) is a publicly traded Delaware limited partnership that was formed in December 2001, and commenced operations on January 31, 2003. The unaudited condensed consolidated financial statements include the accounts of the Partnership and its wholly-owned subsidiaries Dorchester Minerals Oklahoma LP, Dorchester Minerals Oklahoma GP, Inc., Maecenas Minerals LLP, Dorchester-Maecenas GP LLC, The Buffalo Co., A Limited Partnership, and DMLPTBC GP LLC. The accompanying unaudited condensed consolidated financial statements of the Partnership have been prepared in accordance with generally accepted accounting principles in the United States ("U.S. GAAP") and pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”). The unaudited condensed consolidated financial statements reflect all adjustments (consisting only of normal and recurring adjustments unless indicated otherwise) that are, in the opinion of management, necessary for the fair presentation of our financial position and operating results for the interim period. Interim period results are not necessarily indicative of the results for the calendar year. For more information regarding limitations on the forward-looking statements contained herein, see page 1 of this quarterly report on Form 10 -Q. Per-unit information is calculated by dividing the income or loss applicable to holders of our Partnership’s common units by the weighted average number of units outstanding. The Partnership has no potentially dilutive securities and, consequently, basic and diluted income per unit do not differ. The accompanying unaudited condensed consolidated financial statements and related notes should be read in conjunction with the consolidated financial statements and notes thereto included in the Partnership’s 2018 Annual Report on Form 10 -K. The accompanying unaudited condensed consolidated financial statements include the consolidated results of the Partnership. All significant intercompany balances and transactions have been eliminated in consolidation. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. For example, estimates of uncollected revenues and unpaid expenses from Royalty properties (which are interests in oil and natural gas leases that give the Partnership the right to receive a portion of the production from the leased acreage, without bearing the costs of such production) and net profits overriding royalty interests (referred to as the Net Profits Interests, or “NPIs”) operated by non-affiliated entities are particularly subjective due to our inability to gain accurate and timely information. Therefore, actual results could differ from those estimates. Revenue Recognition – Revenues from Royalty properties and NPIs are recorded under the cash receipts approach as directly received from the remitters’ statement accompanying the revenue check. Since the revenue checks are generally received two to four months after the production month, the Partnership accrues for revenue earned but not received by estimating production volumes and product prices. Revenues from lease bonus payments are recorded upon receipt. The lease bonus is separate from the lease itself and is recognized as revenue to the Partnership upon receipt of payment. The Partnership generates lease bonus revenue by leasing its mineral interests to exploration and production companies, and includes proceeds from assignments of leasehold interests where the Partnership retains an interest. A lease agreement represents the Partnership’s contract with a lessee and generally transfers the rights to develop oil or natural gas, grants the Partnership a right to a specified royalty interest, and requires that drilling and completion operations commence within a specified time period. The Partnership does not record revenue for unsatisfied or partially unsatisfied performance obligations.

Note 2 - Acquisition for Units	9 Months Ended
Note 2 - Acquisition for Units	Sep. 30, 2019
Notes to Financial Statements
Acquisition of Producing and Nonproducing Royalty and Mineral Rights [Text Block]	2 Acquisition for Units: On March 29, 2019, pursuant to a Contribution and Exchange Agreement with H. Huffman & Co., A Limited Partnership, an Oklahoma limited partnership (“HHC”), The Buffalo Co., A Limited Partnership, an Oklahoma limited partnership (“TBC” and together with HHC, the “Acquired Entities”), Huffman Oil Co., L.L.C., an Oklahoma limited liability company, and the equity holders of the Acquired Entities, the Partnership acquired (i) a 96.97% net profits interest in certain working interests in various oil and gas properties owned by HHC, (ii) all of the minerals and royalty interests held by HHC, and (iii) all of the minerals and royalty interests held by TBC in exchange for 2,400,000 common units representing limited partnership interests in the Partnership (“Common Units”) valued at $43.8 million and issued pursuant to the Partnership's acquisition shelf registration statements on Form S- 4. The Acquired Entities were accounted for as an acquisition of assets under U.S. GAAP. Accordingly, the cost of the acquisition was allocated on a relative fair value basis and transaction costs were capitalized as a component of the cost of the assets acquired. The unaudited condensed consolidated balance sheet as of September 30, 2019 includes $42.9 million in net property additions. Net property additions includes $4.3 million of unproved properties acquired that were recorded to the oil and natural gas properties full cost pool, thereby accelerating the costs subject to depletion. The Partnership subsequently filed an acquisition shelf registration statement on Form S- 4 that became effective June 6, 2019 and a shelf registration statement on Form S- 3 that became effective August 21, 2019. 20,000,000 units remain available for issuance under the Partnership's registration statements.

Note 4 - Distributions to Holders of Common Units

9 Months Ended

Sep. 30, 2019

Notes to Financial Statements

Partners' Capital Notes Disclosure [Text Block]

Distributions to Holders of Common Units:

Unitholder cash distributions per common unit are as follows:

	Per Unit Amount
	2019		2018
First quarter	$	0.482315	$	0.418449
Second quarter	$	0.515016	$	0.537264
Third quarter	$	0.499055	$	0.394813
Fourth quarter			$	0.516572

Distributions beginning with the

first

quarter of

2019

were paid on

34,679,774

units and distributions in

2018

were paid on

32,279,774

units. The

third

quarter

2019

distribution will be paid on

November 7, 2019.

Fourth quarter distributions shown above are paid in the

first

calendar quarter of the following year. Our partnership agreement requires the

fourth

quarter cash distribution to be paid by

February

14,

2020.

Note 5 - New Accounting Pronouncements	9 Months Ended
Note 5 - New Accounting Pronouncements	Sep. 30, 2019
Notes to Financial Statements
Description of New Accounting Pronouncements Not yet Adopted [Text Block]	5 New Accounting Pronouncements: In February 2016, the Financial Standards Accounting Board (“FASB”) issued a new standard related to leases, Accounting Standards Codification (“ASC”) 842 – Leases (“ASC 842” ) to increase transparency and comparability among organizations by requiring the recognition of right-of-use (“ROU”) assets and lease liabilities on the balance sheet, including the recognition of ROU assets and lease liabilities for operating leases. ASC 842 requires certain disclosures to meet the objective of enabling users of financial statements to assess the amount, timing and uncertainty of cash flows arising from leases. The Partnership adopted ASC 842 on January 1, 2019, using the modified retrospective transition method as of the adoption date, which did not require the Partnership to adjust comparative periods. In addition, the Partnership elected the package of practical expedients permitted under the transition guidance within ASC 842, which among other things, allowed the Partnership to carry forward the historical lease classification. The Partnership also elected the land easements practical expedient, which allowed the Partnership to carry forward the accounting treatment for land easements on existing agreements. The Partnership determines if an arrangement is a lease at inception. Upon lease commencement, the Partnership concluded its office lease was an operating lease and therefore, on January 1, 2019, the Partnership recognized a ROU asset of $1.9 million, excluding lease incentives, and a lease liability of $2.7 million related to its office lease. The difference between the ROU asset and operating lease liability was recorded as an adjustment to deferred rent incentive. The adoption of ASC 842 had no impact on Partnership capital, the consolidated statements of income or the consolidated statements of cash flows. In preparation for the adoption of ASC 842, the Partnership implemented internal controls to identify arrangements that may contain a lease.

Note 6 - Leases

9 Months Ended

Sep. 30, 2019

Notes to Financial Statements

Lessee, Operating Leases [Text Block]

Leases:

The Partnership leases its office space at

3838

Oak Lawn Avenue, Suite

300,

Dallas, Texas, through an operating lease.

Operating lease ROU assets and operating lease liabilities are recognized based on the present value of lease payments over the lease term at commencement date. As the Partnership’s lease does

not

provide an implicit rate of return and as the Partnership is precluded from incurring any borrowings above a nominal amount under its partnership agreement, the Partnership used a discount rate commensurate with the incremental borrowing rate of a group of peers based on information available at the adoption date in determining the present value of lease payments. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term.

	Three Months Ended		Nine Months Ended
	September 30, 2019		September 30, 2019		CONDENSED CONSOLIDATED I NCOME STATEMENTS
	(In Thousands)		(In Thousands)
Lease Expense
Operating lease expense	$	66	$	198	General and administrative expenses

	Nine Months Ended
	September 30, 2019
	(In Thousands)
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	$	177

	As of
	September 30, 2019

Weighted-Average Remaining Lease Term (months)
Operating lease		113

Weighted-Average Discount Rate
Operating lease		5	%

Maturities of lease liabilities are as follows:

	As of
	September 30, 2019
	(In Thousands)
2019	$	77
2020		332
2021		338
2022		344
2023		350
Thereafter		1,903
Total lease payments		3,344
Less amount representing interest		(774	)
Total lease obligation	$	2,570

Significant Accounting Policies (Policies)	9 Months Ended
Significant Accounting Policies (Policies)	Sep. 30, 2019
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	Basis of Presentation: Dorchester Minerals, L.P. (the “Partnership”) is a publicly traded Delaware limited partnership that was formed in December 2001, and commenced operations on January 31, 2003. The unaudited condensed consolidated financial statements include the accounts of the Partnership and its wholly-owned subsidiaries Dorchester Minerals Oklahoma LP, Dorchester Minerals Oklahoma GP, Inc., Maecenas Minerals LLP, Dorchester-Maecenas GP LLC, The Buffalo Co., A Limited Partnership, and DMLPTBC GP LLC. The accompanying unaudited condensed consolidated financial statements of the Partnership have been prepared in accordance with generally accepted accounting principles in the United States ("U.S. GAAP") and pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”). The unaudited condensed consolidated financial statements reflect all adjustments (consisting only of normal and recurring adjustments unless indicated otherwise) that are, in the opinion of management, necessary for the fair presentation of our financial position and operating results for the interim period. Interim period results are not necessarily indicative of the results for the calendar year. For more information regarding limitations on the forward-looking statements contained herein, see page 1 of this quarterly report on Form 10 -Q. Per-unit information is calculated by dividing the income or loss applicable to holders of our Partnership’s common units by the weighted average number of units outstanding. The Partnership has no potentially dilutive securities and, consequently, basic and diluted income per unit do not differ. The accompanying unaudited condensed consolidated financial statements and related notes should be read in conjunction with the consolidated financial statements and notes thereto included in the Partnership’s 2018 Annual Report on Form 10 -K. The accompanying unaudited condensed consolidated financial statements include the consolidated results of the Partnership. All significant intercompany balances and transactions have been eliminated in consolidation. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. For example, estimates of uncollected revenues and unpaid expenses from Royalty properties (which are interests in oil and natural gas leases that give the Partnership the right to receive a portion of the production from the leased acreage, without bearing the costs of such production) and net profits overriding royalty interests (referred to as the Net Profits Interests, or “NPIs”) operated by non-affiliated entities are particularly subjective due to our inability to gain accurate and timely information. Therefore, actual results could differ from those estimates.
Revenue from Contract with Customer [Policy Text Block]	Revenue Recognition – Revenues from Royalty properties and NPIs are recorded under the cash receipts approach as directly received from the remitters’ statement accompanying the revenue check. Since the revenue checks are generally received two to four months after the production month, the Partnership accrues for revenue earned but not received by estimating production volumes and product prices. Revenues from lease bonus payments are recorded upon receipt. The lease bonus is separate from the lease itself and is recognized as revenue to the Partnership upon receipt of payment. The Partnership generates lease bonus revenue by leasing its mineral interests to exploration and production companies, and includes proceeds from assignments of leasehold interests where the Partnership retains an interest. A lease agreement represents the Partnership’s contract with a lessee and generally transfers the rights to develop oil or natural gas, grants the Partnership a right to a specified royalty interest, and requires that drilling and completion operations commence within a specified time period. The Partnership does not record revenue for unsatisfied or partially unsatisfied performance obligations.

Note 6 - Leases (Tables)

9 Months Ended

Sep. 30, 2019

Notes Tables

Lease, Cost [Table Text Block]

	Three Months Ended		Nine Months Ended
	September 30, 2019		September 30, 2019		CONDENSED CONSOLIDATED I NCOME STATEMENTS
	(In Thousands)		(In Thousands)
Lease Expense
Operating lease expense	$	66	$	198	General and administrative expenses

Lessee, Operating Lease, Cash Flow [Table Text Block]

	Nine Months Ended
	September 30, 2019
	(In Thousands)
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	$	177

Lessee, Operating Lease, Balance Sheet [Table Text Block]

	As of
	September 30, 2019

Weighted-Average Remaining Lease Term (months)
Operating lease		113

Weighted-Average Discount Rate
Operating lease		5	%

Lessee, Operating Lease, Liability, Maturity [Table Text Block]

	As of
	September 30, 2019
	(In Thousands)
2019	$	77
2020		332
2021		338
2022		344
2023		350
Thereafter		1,903
Total lease payments		3,344
Less amount representing interest		(774	)
Total lease obligation	$	2,570

Note 1 - Basis of Presentation (Details Textual) shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2019 USD ($) shares
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount \| shares	0
Contract with Customer, Liability, Total \| $	$ 0

Note 2 - Acquisition for Units (Details Textual) - USD ($) $ in Millions	Mar. 29, 2019	Aug. 21, 2019
Limited Partners' Capital Account, Units Authorized		20,000,000
HHC [Member]
Business Acquisition, Percentage of Net Profits Interest Acquired	96.97%
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment, Total	$ 42.9
Impairment of Oil and Gas Properties	$ 4.3
HHC [Member] \| Partnership Interest [Member]
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares	2,400,000
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable	$ 43.8

Note 6 - Leases - Supplemental Balance Sheet Information (Details)	Sep. 30, 2019
Operating lease, weighted average remaining lease term (Month)	9 years 150 days
Operating lease, weighted average discount rate	5.00%

Note 6 - Leases - Maturities of Lease Liabilities (Details) $ in Thousands	Sep. 30, 2019 USD ($)
2019	$ 77
2020	332
2021	338
2022	344
2023	350
Thereafter	1,903
Total lease payments	3,344
Less amount representing interest	(774)
Total lease obligation	$ 2,570

Note 3 - Commitments and Contingencies	9 Months Ended
Note 3 - Commitments and Contingencies	Sep. 30, 2019
Notes to Financial Statements
Commitments and Contingencies Disclosure [Text Block]	3 Commitments and Contingencies: The Partnership and Dorchester Minerals Operating L.P., a Delaware limited partnership owned directly and indirectly by our general partner, are involved in legal and/or administrative proceedings arising in the ordinary course of their businesses, none of which have predictable outcomes and none of which are believed to have any significant effect on our consolidated financial position, cash flows, or operating results.

Note 5 - New Accounting Pronouncements (Details Textual) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019
Operating Lease, Right-of-Use Asset	$ 1,695
Operating Lease, Liability, Total	$ 2,570
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset		$ 1,900
Operating Lease, Liability, Total		$ 2,700

Note 4 - Distributions to Holders of Common Units (Details Textual) - shares	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Distribution Made to Limited Partner, Unit Distribution	34,679,774	32,279,774

Note 4 - Distributions to Holders of Common Units - Unitholder Cash Distributions Per Common Unit (Details) - $ / shares	3 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018
Cash distribution per unit (in dollars per share)	$ 0.499055	$ 0.515016	$ 0.482315	$ 0.516572	$ 0.394813	$ 0.537264	$ 0.418449

Note 6 - Leases - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Jun. 30, 2019	Sep. 30, 2019
General and Administrative Expense [Member]
Operating lease expense	$ 66	$ 198

Note 6 - Leases - Supplemental Cash Flow Information (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019 USD ($)
Operating cash flows from operating leases	$ 177