Supplemental Condensed Consolidated Financial Information (Condensed Consolidating Statements of Income) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Condensed Financial Statements, Captions [Line Items]
Revenues	$ 220,058	$ 188,488	$ 628,493	$ 534,793
Expenses:
Operating costs	107,305	106,774	320,553	298,948
Depreciation, depletion, and amortization	63,537	54,533	178,976	151,545
General and administrative	9,278	9,235	28,752	26,902
Gain on disposition of assets	(253)	(81)	(575)	(1,153)
Total operating costs	179,867	170,461	527,706	476,242
Income (loss) from operations	40,191	18,027	100,787	58,551
Interest, net	(7,945)	(9,944)	(25,678)	(28,807)
Gain (loss) on derivatives	(4,385)	(2,614)	(25,608)	21,019
Other, net	6	5	17	14
Income (loss) before income taxes	27,867	5,474	49,518	50,777
Income tax expense (benefit)	6,744	1,769	12,380	22,084
Equity in net earnings from investment in subsidiaries, net of taxes	0	0	0	0
Net income	21,123	3,705	37,138	28,693
Less: net income attributable to non-controlling interest	2,224	0	4,586	0
Net income attributable to Unit Corporation	18,899	3,705	32,552	28,693
Consolidating Adjustments [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues	(32,459)	(21,627)	(82,974)	(57,697)
Expenses:
Operating costs	(31,273)	(21,026)	(80,540)	(56,720)
Depreciation, depletion, and amortization	0	0	0	0
General and administrative	0	0	0	0
Gain on disposition of assets	0	0	0	0
Total operating costs	(31,273)	(21,026)	(80,540)	(56,720)
Income (loss) from operations	(1,186)	(601)	(2,434)	(977)
Interest, net	0	0	0	0
Gain (loss) on derivatives	0	0	0	0
Other, net	0	0	0	0
Income (loss) before income taxes	(1,186)	(601)	(2,434)	(977)
Income tax expense (benefit)	0	0	0	0
Equity in net earnings from investment in subsidiaries, net of taxes	(29,077)	(12,377)	(74,360)	(35,786)
Net income	(30,263)	(12,978)	(76,794)	(36,763)
Less: net income attributable to non-controlling interest	0	0	0	0
Net income attributable to Unit Corporation	(30,263)	(12,978)	(76,794)	(36,763)
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues	0	0	0	0
Expenses:
Operating costs	0	0	0	0
Depreciation, depletion, and amortization	1,923	1,913	5,759	5,558
General and administrative	0	0	0	0
Gain on disposition of assets	0	0	(30)	(813)
Total operating costs	1,923	1,913	5,729	4,745
Income (loss) from operations	(1,923)	(1,913)	(5,729)	(4,745)
Interest, net	(7,564)	(9,776)	(24,844)	(28,276)
Gain (loss) on derivatives	(4,385)	(2,614)	(25,608)	21,019
Other, net	6	5	17	14
Income (loss) before income taxes	(13,866)	(14,298)	(56,164)	(11,988)
Income tax expense (benefit)	(3,688)	(5,626)	(14,356)	(4,895)
Equity in net earnings from investment in subsidiaries, net of taxes	29,077	12,377	74,360	35,786
Net income	18,899	3,705	32,552	28,693
Less: net income attributable to non-controlling interest	0	0	0	0
Net income attributable to Unit Corporation	18,899	3,705	32,552	28,693
Combined Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues	169,635	141,058	478,529	393,858
Expenses:
Operating costs	71,646	73,197	215,355	199,143
Depreciation, depletion, and amortization	50,349	41,740	139,724	113,440
General and administrative	9,252	7,083	26,136	20,880
Gain on disposition of assets	(237)	(67)	(450)	(282)
Total operating costs	131,010	121,953	380,765	333,181
Income (loss) from operations	38,625	19,105	97,764	60,677
Interest, net	0	0	0	0
Gain (loss) on derivatives	0	0	0	0
Other, net	(1)	0	0	0
Income (loss) before income taxes	38,624	19,105	97,764	60,677
Income tax expense (benefit)	9,839	7,003	25,299	25,357
Equity in net earnings from investment in subsidiaries, net of taxes	0	0	0	0
Net income	28,785	12,102	72,465	35,320
Less: net income attributable to non-controlling interest	0	0	0	0
Net income attributable to Unit Corporation	28,785	12,102	72,465	35,320
Combined Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues	82,882	69,057	232,938	198,632
Expenses:
Operating costs	66,932	54,603	185,738	156,525
Depreciation, depletion, and amortization	11,265	10,880	33,493	32,547
General and administrative	26	2,152	2,616	6,022
Gain on disposition of assets	(16)	(14)	(95)	(58)
Total operating costs	78,207	67,621	221,752	195,036
Income (loss) from operations	4,675	1,436	11,186	3,596
Interest, net	(381)	(168)	(834)	(531)
Gain (loss) on derivatives	0	0	0	0
Other, net	1	0	0	0
Income (loss) before income taxes	4,295	1,268	10,352	3,065
Income tax expense (benefit)	593	392	1,437	1,622
Equity in net earnings from investment in subsidiaries, net of taxes	0	0	0	0
Net income	3,702	876	8,915	1,443
Less: net income attributable to non-controlling interest	2,224	0	4,586	0
Net income attributable to Unit Corporation	$ 1,478	$ 876	$ 4,329	$ 1,443