Supplemental Condensed Consolidated Financial Information (Condensed Consolidating Balance Sheets) (Details) - USD ($) $ in Thousands		Dec. 31, 2018		Jan. 01, 2018	Dec. 31, 2017		Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents		$ 6,452			$ 701		$ 893	$ 835
Accounts receivable		119,397			111,512
Materials and supplies		473			505
Current derivative assets		12,870			721
Current income taxes receivable		2,054			61
Assets held for sale		22,511			0
Prepaid expenses and other		11,356			6,172
Total current assets		175,113			119,672
Oil and Gas Property [Abstract]
Proved properties		6,018,568			5,712,813		5,446,305
Unproved properties not being amortized		330,216			296,764		314,867
Drilling equipment		1,284,419			1,593,611
Gas gathering and processing equipment		767,388			726,236
Saltwater disposal systems		68,339			62,618
Corporate land and building		59,081			59,080
Transportation equipment		29,524			29,631
Other		57,507			53,439
Property, plant and equipment, gross, total		8,615,042			8,534,192
Less accumulated depreciation, depletion, amortization, and impairment		6,182,726			6,151,450
Net property and equipment		2,432,316			2,382,742
Intercompany receivable		0			0
Goodwill		62,808			62,808
Investments		1,500			1,500
Other assets		26,316			14,730
Total assets		2,698,053	[1]		2,581,452	[1]	2,479,303
Current liabilities:
Accounts payable		149,945			112,648
Accrued liabilities		49,664			48,523
Current derivative liabilities		0			7,763
Current portion of other long-term liabilities		14,250		$ 15,750	13,002
Total current liabilities		213,859			181,936
Intercompany debt		0			0
Long-term debt					178,000
Bonds payable less debt issuance costs		644,475			642,276
Non-current derivative liabilities		293			0
Other long-term liabilities		101,234		109,940	100,203
Deferred income taxes		144,748		133,064	133,477
Shareholders' equity:
Preferred stock, $1.00 par value, 5,000,000 shares authorized, none issued		0			0
Common Stock, $0.20 par value, 175,000,000 shares authorized		10,414			10,280
Capital in excess of par value		628,108			535,815
Contributions from Unit		0
Accumulated other comprehensive income (loss)		(481)		76	63		0	0
Retained earnings		752,840		$ 798,128	799,402
Total shareholders' equity attributable to Unit Corporation		1,390,881			1,345,560
Non-controlling interests in consolidated subsidiaries		202,563			0
Total shareholders' equity		1,593,444			1,345,560		1,194,070	1,313,580
Total liabilities and shareholders' equity	[1]	2,698,053			2,581,452
Consolidating Adjustments
Current assets:
Cash and cash equivalents		0			0		0	0
Accounts receivable		(14,344)			(6,978)
Materials and supplies		0			0
Current derivative assets		0			0
Current income taxes receivable		0			0
Assets held for sale		0
Prepaid expenses and other		0			0
Total current assets		(14,344)			(6,978)
Oil and Gas Property [Abstract]
Proved properties		0			0
Unproved properties not being amortized		0			0
Drilling equipment		0			0
Gas gathering and processing equipment		0			0
Saltwater disposal systems		0			0
Corporate land and building		0			0
Transportation equipment		0			0
Other		0			0
Property, plant and equipment, gross, total		0			0
Less accumulated depreciation, depletion, amortization, and impairment		0			0
Net property and equipment		0			0
Intercompany receivable		(950,916)			(1,155,725)
Goodwill		0			0
Investments		(1,160,444)			(1,044,709)
Other assets		0			0
Total assets		(2,125,704)			(2,207,412)
Current liabilities:
Accounts payable		(13,576)			(6,978)
Accrued liabilities		(468)			0
Current derivative liabilities					0
Current portion of other long-term liabilities		0			0
Total current liabilities		(14,044)			(6,978)
Intercompany debt		(950,916)			(1,155,725)
Long-term debt					0
Bonds payable less debt issuance costs		0			0
Non-current derivative liabilities		0
Other long-term liabilities		(300)			0
Deferred income taxes		0			0
Shareholders' equity:
Preferred stock, $1.00 par value, 5,000,000 shares authorized, none issued		0			0
Common Stock, $0.20 par value, 175,000,000 shares authorized		0			0
Capital in excess of par value		(242,963)			(61,470)
Contributions from Unit		(792)
Accumulated other comprehensive income (loss)		0			0
Retained earnings		(916,689)			(983,239)
Total shareholders' equity attributable to Unit Corporation		(1,160,444)			(1,044,709)
Non-controlling interests in consolidated subsidiaries		0			0
Total shareholders' equity		(1,160,444)			(1,044,709)
Total liabilities and shareholders' equity		(2,125,704)			(2,207,412)
Parent
Current assets:
Cash and cash equivalents		403			510		517	510
Accounts receivable		2,539			154
Materials and supplies		0			0
Current derivative assets		12,870			721
Current income taxes receivable		243			61
Assets held for sale		0
Prepaid expenses and other		5,103			2,925
Total current assets		21,158			4,371
Oil and Gas Property [Abstract]
Proved properties		0			0
Unproved properties not being amortized		0			0
Drilling equipment		0			0
Gas gathering and processing equipment		0			0
Saltwater disposal systems		0			0
Corporate land and building		0			0
Transportation equipment		9,273			9,270
Other		28,584			28,039
Property, plant and equipment, gross, total		37,857			37,309
Less accumulated depreciation, depletion, amortization, and impairment		27,504			21,268
Net property and equipment		10,353			16,041
Intercompany receivable		950,916			1,155,725
Goodwill		0			0
Investments		1,160,444			1,044,709
Other assets		5,115			5,373
Total assets		2,147,986			2,226,219
Current liabilities:
Accounts payable		8,697			13,124
Accrued liabilities		28,230			26,165
Current derivative liabilities					7,763
Current portion of other long-term liabilities		812			657
Total current liabilities		37,739			47,709
Intercompany debt		0			0
Long-term debt					178,000
Bonds payable less debt issuance costs		644,475			642,276
Non-current derivative liabilities		293
Other long-term liabilities		13,134			11,257
Deferred income taxes		60,983			1,480
Shareholders' equity:
Preferred stock, $1.00 par value, 5,000,000 shares authorized, none issued		0			0
Common Stock, $0.20 par value, 175,000,000 shares authorized		10,414			10,280
Capital in excess of par value		628,108			535,815
Contributions from Unit		0
Accumulated other comprehensive income (loss)		0			0
Retained earnings		752,840			799,402
Total shareholders' equity attributable to Unit Corporation		1,391,362			1,345,497
Non-controlling interests in consolidated subsidiaries		0			0
Total shareholders' equity		1,391,362			1,345,497
Total liabilities and shareholders' equity		2,147,986			2,226,219
Combined Guarantor Subsidiaries
Current assets:
Cash and cash equivalents		208			191		376	325
Accounts receivable		94,526			89,622
Materials and supplies		473			505
Current derivative assets		0			0
Current income taxes receivable		1,811			0
Assets held for sale		22,511
Prepaid expenses and other		3,560			2,370
Total current assets		123,089			92,688
Oil and Gas Property [Abstract]
Proved properties		6,018,568			5,712,813
Unproved properties not being amortized		330,216			296,764
Drilling equipment		1,284,419			1,593,611
Gas gathering and processing equipment		0			0
Saltwater disposal systems		68,339			62,618
Corporate land and building		59,081			59,080
Transportation equipment		17,165			17,423
Other		28,923			25,400
Property, plant and equipment, gross, total		7,806,711			7,767,709
Less accumulated depreciation, depletion, amortization, and impairment		5,790,481			5,807,757
Net property and equipment		2,016,230			1,959,952
Intercompany receivable		0			0
Goodwill		62,808			62,808
Investments		1,500			1,500
Other assets		5,293			6,328
Total assets		2,208,920			2,123,276
Current liabilities:
Accounts payable		122,610			87,514
Accrued liabilities		16,409			19,134
Current derivative liabilities					0
Current portion of other long-term liabilities		6,563			8,501
Total current liabilities		145,582			115,149
Intercompany debt		948,707			870,582
Long-term debt					0
Bonds payable less debt issuance costs		0			0
Non-current derivative liabilities		0
Other long-term liabilities		73,713			77,566
Deferred income taxes		83,765			85,443
Shareholders' equity:
Preferred stock, $1.00 par value, 5,000,000 shares authorized, none issued		0			0
Common Stock, $0.20 par value, 175,000,000 shares authorized		0			0
Capital in excess of par value		45,921			45,921
Contributions from Unit		0
Accumulated other comprehensive income (loss)		(481)			63
Retained earnings		911,713			928,552
Total shareholders' equity attributable to Unit Corporation		957,153			974,536
Non-controlling interests in consolidated subsidiaries		0			0
Total shareholders' equity		957,153			974,536
Total liabilities and shareholders' equity		2,208,920			2,123,276
Combined Non-Guarantor Subsidiaries
Current assets:
Cash and cash equivalents		5,841			0		$ 0	$ 0
Accounts receivable		36,676			28,714
Materials and supplies		0			0
Current derivative assets		0			0
Current income taxes receivable		0			0
Assets held for sale		0
Prepaid expenses and other		2,693			877
Total current assets		45,210			29,591
Oil and Gas Property [Abstract]
Proved properties		0			0
Unproved properties not being amortized		0			0
Drilling equipment		0			0
Gas gathering and processing equipment		767,388			726,236
Saltwater disposal systems		0			0
Corporate land and building		0			0
Transportation equipment		3,086			2,938
Other		0			0
Property, plant and equipment, gross, total		770,474			729,174
Less accumulated depreciation, depletion, amortization, and impairment		364,741			322,425
Net property and equipment		405,733			406,749
Intercompany receivable		0			0
Goodwill		0			0
Investments		0			0
Other assets		15,908			3,029
Total assets		466,851			439,369
Current liabilities:
Accounts payable		32,214			18,988
Accrued liabilities		5,493			3,224
Current derivative liabilities					0
Current portion of other long-term liabilities		6,875			3,844
Total current liabilities		44,582			26,056
Intercompany debt		2,209			285,143
Long-term debt					0
Bonds payable less debt issuance costs		0			0
Non-current derivative liabilities		0
Other long-term liabilities		14,687			11,380
Deferred income taxes		0			46,554
Shareholders' equity:
Preferred stock, $1.00 par value, 5,000,000 shares authorized, none issued		0			0
Common Stock, $0.20 par value, 175,000,000 shares authorized		0			0
Capital in excess of par value		197,042			15,549
Contributions from Unit		792
Accumulated other comprehensive income (loss)		0			0
Retained earnings		4,976			54,687
Total shareholders' equity attributable to Unit Corporation		202,810			70,236
Non-controlling interests in consolidated subsidiaries		202,563			0
Total shareholders' equity		405,373			70,236
Total liabilities and shareholders' equity		$ 466,851			$ 439,369

[1] Unit Corporation's consolidated total assets as of December 31, 2018 include current and long-term assets of its variable interest entity (VIE) (Superior) of $41.7 million and $421.6 million, respectively, which can only be used to settle obligations of the VIE. Unit Corporation's consolidated total liabilities as of December 31, 2018 include current and long-term liabilities of the VIE of $42.8 million and $14.7 million, respectively, for which the creditors of the VIE have no recourse to Unit Corporation. See Note 16 – Variable Interest Entity Arrangements.