Document And Entity Information - shares	9 Months Ended
Document And Entity Information - shares	Sep. 30, 2017	Nov. 03, 2017
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 Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Entity Common Stock, Shares Outstanding (in shares)		32,279,774
Document Type	10-Q
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q3
Amendment Flag	false

Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 11,557	$ 8,212
Trade and other receivables	5,210	4,332
Net profits interests receivable - related party	2,321	2,225
Total current assets	19,088	14,769
Other non-current assets	31	19
Property and leasehold improvements - at cost:
Oil and natural gas properties (full cost method)	363,186	340,563
Accumulated full cost depletion	(294,583)	(288,163)
Total	68,603	52,400
Total assets	88,305	67,211
Current liabilities:
Accounts payable and other current liabilities	1,774	252
Current portion of deferred rent incentive	15	23
Total current liabilities	1,789	275
Deferred rent incentive less current portion	462
Total liabilities	2,251	275
Commitments and contingencies (Note 2)
Partnership capital:
General partner	1,693	1,809
Unitholders	84,361	65,127
Total partnership capital	86,054	66,936
Total liabilities and partnership capital	88,305	67,211
Leasehold Improvements [Member]
Property and leasehold improvements - at cost:
Leasehold improvements	1,208	625
Accumulated amortization	(625)	(602)
Total	$ 583	$ 23

Condensed Consolidated Income Statements (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Operating revenues:
Lease bonus	$ 43	$ 865	$ 1,799	$ 2,509
Other	201	17	644	227
Total operating revenues	12,480	10,679	37,760	26,814
Costs and expenses:
Operating, including production taxes	1,320	902	3,358	2,180
Depreciation, depletion and amortization	2,795	2,080	6,443	6,571
General and administrative expenses	1,141	1,050	3,764	3,967
Total costs and expenses	5,256	4,032	13,565	12,718
Net income	7,224	6,647	24,195	14,096
Allocation of net income:
General partner	273	230	903	496
Unitholders	$ 6,951	$ 6,417	$ 23,292	$ 13,600
Net income per common unit (basic and diluted) (in dollars per share)	$ 0.22	$ 0.21	$ 0.75	$ 0.44
Weighted average common units outstanding (in shares)	32,280	30,675	31,222	30,675
Royalty Revenue [Member]
Operating revenues:
Revenues	$ 11,499	$ 8,208	$ 32,611	$ 20,758
Net Profits Interests [Member]
Operating revenues:
Revenues	$ 737	$ 1,589	$ 2,706	$ 3,320

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Net cash provided by operating activities	$ 31,274	$ 21,563
Cash flows provided by investing activities:
Cash contributed in acquisition of royalty interests	437
Capital expenditures	(106)
Total cash flows provided by investing activities	(331)
Cash flows used in financing activities:
Distributions paid to general partner and unitholders	(28,260)	(19,203)
Increase in cash and cash equivalents	3,345	2,360
Cash and cash equivalents at beginning of period	8,212	7,136
Cash and cash equivalents at end of period	11,557	9,496
Non-cash investing and financing activities:
Fair value of common units issued for acquisition of royalty interests	$ 23,183

Note 1 - Basis of Presentation	9 Months Ended
Note 1 - Basis of Presentation	Sep. 30, 2017
Notes to Financial Statements
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	1 Basis of Presentation: Dorchester Minerals, L.P. is a publicly traded Delaware limited partnership that was formed in December 2001, and commenced operations on January 31, 2003. The condensed consolidated financial statements include the accounts of Dorchester Minerals, L.P. and its wholly-owned subsidiaries Dorchester Minerals Oklahoma LP, Dorchester Minerals Oklahoma GP, Inc., Maecenas Minerals LLP, and Dorchester-Maecenas GP LLC. All significant intercompany balances and transactions have been eliminated in consolidation. The 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 statement 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. See “Management’s Discussion and Analysis of Financial Condition and Results of Operations” for additional information. 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 dilutive income per unit do not differ. These interim financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in the Partnership’s annual report on Form 10 -K for the year ended December 31, 2016. Fair Value of Financial Instruments - The carrying amount of cash and cash equivalents, trade receivables and payables approximates fair value because of the short maturity of those instruments. These estimated fair values may not be representative of actual values of the financial instruments that could have been realized as of quarter close or that will be realized in the future.

Note 2 - Commitments and Contingencies	9 Months Ended
Note 2 - Commitments and Contingencies	Sep. 30, 2017
Notes to Financial Statements
Commitments and Contingencies Disclosure [Text Block]	2 C ommitments and Contingencies : The Partnership and Dorchester Minerals Operating LP, 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. Operating Leases - We have entered into an operating lease agreement in the ordinary course of our business activities. The third amendment to our office lease was signed on April 17, 2017, for a term of 129 months beginning June 1, 2018. The lease is for our office space at 3838 Oak Lawn Avenue, Suite 300, Dallas, Texas, and now expires in 2029. Under the third amendment to the office lease, monthly rental payments will range from $25,000 - $30,000 and the Partnership will receive a tenant improvement allowance of approximately $700,000. The Partnership recognizes a deferred rent liability for the rent escalations when the amount of straight-line rent exceeds the lease payments, and reduces the deferred rent liability when the lease payments exceed the straight-line rent expense. For the tenant improvement allowance, the Partnership will record a deferred rent liability and will amortize the deferred rent over the lease term as a reduction to rent expense once in use.

Note 3 - Acquisition for Common Units	9 Months Ended
Note 3 - Acquisition for Common Units	Sep. 30, 2017
Notes to Financial Statements
Acquisition of Producing and Nonproducing Royalty and Mineral Rights [Text Block]	3 Acquisition for Common Units: On June 30, 2017, pursuant to a Contribution, Exchange and Purchase Agreement with DSD Royalty, LLC, a Texas limited liability company (“DSD”), the Partnership acquired producing and nonproducing royalty and mineral interests located in the Midland Basin in exchange for consideration valued at approximately $23,183,000, half in cash (the “Cash Consideration”) and half in common units representing limited partner interests in the Partnership (“Common Units”), based on a price of $14.98 per Common Unit (calculated based on the average closing price of Common Units during the period beginning 15 trading days immediately prior to the closing date and ending two trading days prior to the closing date) (the “DSD Agreement”). Prior to the closing of the DSD Agreement, the Partnership entered into a Participation Agreement with certain officers of the Partnership and entities affiliated with certain officers and directors of the Partnership (the “Participants”), pursuant to which the Partnership agreed to assign an undivided 50% interest in its rights under the DSD Agreement to the Participants in exchange for the Participants’ assumption of the obligation to pay the Cash Consideration on behalf of the Partnership (the “Participation Agreement”). On June 30, 2017, in connection with the closing of the DSD Agreement, the Participants contributed to the Partnership their respective assets received pursuant to the Participation Agreement in exchange for common units of the Partnership based on a price of $14.98 per Common Unit (calculated in the same manner as the price of Common Units issued pursuant to the DSD Agreement) pursuant to Contribution and Exchange Agreements with the Partnership (the “Participant Contribution Agreements”). In accordance with the transactions contemplated by the DSD Agreement and the Participant Contribution Agreements, the Partnership issued to DSD and the Participants an aggregate of 1,604,343 Common Units pursuant to the Partnership’s registration statements on Form S- 4. After the issuance, 6,395,657 Common Units remain available under the Partnership’s registration statements on Form S- 4.

Note 4 - Distribution to Holders of Common Units

9 Months Ended

Sep. 30, 2017

Notes to Financial Statements

Partners' Capital Notes Disclosure [Text Block]

istributions to Holders of Common Units

Unitholder cash distributions per common unit since

2015

have been:

	Per Unit Amount
	201 7	201 6	201 5
First quarter	$0.306700	$0.147417	$0.306553

Second quarter	$0.322965	$0.257977	$0.167430

Third quarter	$0.284650	$0.252224	$0.194234

Fourth quarter		$0.241475	$0.199076

Distributions beginning with the

second

quarter of

2017

were paid on

32,279,774

units; previous distributions set forth above were paid on

30,675,431

units. The

third

quarter

2017

distribution will be paid on

November 9, 2017.

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,

2018.

Note 5 - New Accounting Pronouncements	9 Months Ended
Note 5 - New Accounting Pronouncements	Sep. 30, 2017
Notes to Financial Statements
Description of New Accounting Pronouncements Not yet Adopted [Text Block]	5 New Accounting Pronouncements: In May 2014, the FASB issued Accounting Standards Update (ASU) No. 2014 - 09, Revenue from Contracts with Customers (ASU 2014 - 09 ), which supersedes nearly all existing revenue recognition guidance under U.S. GAAP. The guidance requires entities to recognize revenue using the following five -step model: identify the contract with a customer, identify the performance obligations in the contract, determine the transaction price, allocate the transaction price to the performance obligations in the contract, and recognize revenue as the entity satisfies each performance obligation. Adoption of this standard could result in retrospective application, either in the form of recasting all prior periods presented or a cumulative adjustment to equity in the period of adoption. The company plans to adopt this standard using the modified retrospective method upon its effective date. The guidance is effective for annual and interim reporting periods beginning after December 15, 2017. Our Partnership’s revenues are substantially attributable to oil and gas sales. Based on substantial completion of review of our contracts, we believe the timing and presentation of revenues under ASU 2014 - 09 will be materially consistent with our current revenue recognition policy as described above. The Partnership will continue to monitor specific developments for our industry as it relates to ASU 2014 - 09. In February 2016, the FASB issued ASU 2016 - 02, which requires lessees to record most leases on the balance sheet. Under the new guidance, lease classification as either a finance lease or an operating lease will determine how lease-related revenue and expense are recognized. The guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company has lease commitments of approximately $3 million that we believe would be subject to capitalization under ASU 2016 - 02. The lease obligations that will be in place upon adoption of ASU 2016 - 02 may be significantly different than our current obligations. Accordingly, at this time we cannot estimate the amount that will be capitalized when this standard is adopted.

Note 4 - Distribution to Holders of Common Units (Tables)

9 Months Ended

Sep. 30, 2017

Notes Tables

Distributions Made to Limited Partner, by Distribution [Table Text Block]

	Per Unit Amount
	201 7	201 6	201 5
First quarter	$0.306700	$0.147417	$0.306553

Second quarter	$0.322965	$0.257977	$0.167430

Third quarter	$0.284650	$0.252224	$0.194234

Fourth quarter		$0.241475	$0.199076

Note 2 - Commitments and Contingencies (Details Textual) - Office Lease [Member]	Apr. 17, 2017 USD ($)
Lessee, Operating Lease, Term of Contract	10 years 270 days
Tenant Improvement Allowance	$ 700,000
Minimum [Member]
Operating Leases, Future Monthly Payments	25,000
Maximum [Member]
Operating Leases, Future Monthly Payments	$ 30,000

Note 3 - Acquisition for Common Units (Details Textual) - Royalty and Mineral Interests [Member]	Jun. 30, 2017 USD ($) $ / shares shares
Limited Partnership Common Units, Value \| $	$ 23,183,000
Limited Partnership Common Units, Value Per Share \| $ / shares	$ 14.98
Limited Partners' Capital Account, Units Issued	1,604,343
Limited Partners' Capital Account, Units Authorized	6,395,657

Note 1 - Basis of Presentation (Details Textual) shares in Thousands	9 Months Ended
	Sep. 30, 2017 shares
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0

Note 4 - Distribution to Holders of Common Units - Unitholder Cash Distributions Per Common Unit (Details) - $ / shares	3 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015
Cash distribution per unit (in dollars per share)	$ 0.28465	$ 0.322965	$ 0.3067	$ 0.241475	$ 0.252224	$ 0.257977	$ 0.147417	$ 0.199076	$ 0.194234	$ 0.16743	$ 0.306553