Supplemental Condensed Consolidated Financial Information (Condensed Consolidating Balance Sheets) (Details) - USD ($) $ in Thousands		Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents		$ 669		$ 6,452	$ 104,308		$ 701
Accounts receivable, net of allowance for doubtful accounts		89,876		119,397
Materials and supplies		516		473
Current derivative asset		8,513		12,870
Income taxes receivable		2,405		2,054
Assets held for sale		19,500		22,511
Prepaid expenses and other		9,106		6,602
Total current assets		130,585		170,359
Oil and natural gas properties on the full cost method:
Proved properties		6,212,323		6,018,568
Unproved properties not being amortized		336,214		330,216
Drilling equipment		1,284,295		1,284,419
Gas gathering and processing equipment		798,503		767,388
Saltwater disposal systems		69,212		68,339
Corporate land and building		59,080		59,081
Transportation equipment		30,019		29,524
Other		57,900		57,507
Property, plant, and equipment, gross		8,847,546		8,615,042
Less accumulated depreciation, depletion, amortization, and impairment		6,289,575		6,182,726
Net property and equipment		2,557,971		2,432,316
Intercompany receivable		0		0
Goodwill		62,808		62,808
Investments		0		0
Operating right of use asset		8,302		0
Other assets		33,863		32,570
Total assets	[1]	2,793,529		2,698,053
Current liabilities:
Accounts payable		131,129		149,945
Accrued liabilities		45,175		49,664
Current operating lease liability		4,519		0
Current portion of other long-term liabilities		13,887		14,250
Total current liabilities		194,710		213,859
Intercompany debt		0		0
Long-term debt		756,590		644,475
Non-current derivative liability		256		293
Operating lease liability		3,556		0
Other long-term liabilities		102,700		101,234
Deferred income taxes		142,485		144,748
Shareholders' equity:
Preferred stock, $1.00 par value, 5,000,000 shares authorized, none issued		0		0
Common stock, $.20 par value, 175,000,000 shares authorized		10,590		10,414
Capital in excess of par value		638,769		628,108
Contributions from Unit		0		0
Accumulated other comprehensive income (loss)		(487)	$ (457)	(481)	(65)	$ (100)	63
Retained earnings		741,001		752,840
Total shareholders’ equity attributable to Unit Corporation		1,389,873		1,390,881
Non-controlling interests in consolidated subsidiaries		203,359		202,563
Total shareholders' equity		1,593,232	$ 1,595,859	1,593,444	1,643,654	$ 1,357,300	1,345,560
Total liabilities and shareholders' equity	[1]	2,793,529		2,698,053
Consolidating Adjustments [Member]
Current assets:
Cash and cash equivalents		0		0	0		0
Accounts receivable, net of allowance for doubtful accounts		(5,922)		(14,344)
Materials and supplies		0		0
Current derivative asset		0		0
Income taxes receivable		0		0
Assets held for sale		0		0
Prepaid expenses and other		0		0
Total current assets		(5,922)		(14,344)
Oil and natural gas properties on the full cost method:
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		0		0
Less accumulated depreciation, depletion, amortization, and impairment		0		0
Net property and equipment		0		0
Intercompany receivable		(1,046,308)		(950,916)
Goodwill		0		0
Investments		(1,166,768)		(1,160,444)
Operating right of use asset		(57)
Other assets		0		0
Total assets		(2,219,055)		(2,125,704)
Current liabilities:
Accounts payable		(5,921)		(13,576)
Accrued liabilities		(467)		(468)
Current operating lease liability		(6)
Current portion of other long-term liabilities		0		0
Total current liabilities		(6,394)		(14,044)
Intercompany debt		(1,046,308)		(950,916)
Long-term debt		0		0
Non-current derivative liability		0		0
Operating lease liability		(51)
Other long-term liabilities		(506)		(300)
Deferred income taxes		0		0
Shareholders' equity:
Preferred stock, $1.00 par value, 5,000,000 shares authorized, none issued		0		0
Common stock, $.20 par value, 175,000,000 shares authorized		0		0
Capital in excess of par value		(242,963)		(242,963)
Contributions from Unit		(1,145)		(792)
Accumulated other comprehensive income (loss)		0		0
Retained earnings		(921,688)		(916,689)
Total shareholders’ equity attributable to Unit Corporation		(1,165,796)		(1,160,444)
Non-controlling interests in consolidated subsidiaries		0		0
Total shareholders' equity		(1,165,796)		(1,160,444)
Total liabilities and shareholders' equity		(2,219,055)		(2,125,704)
Parent [Member]
Current assets:
Cash and cash equivalents		508		403	97,052		510
Accounts receivable, net of allowance for doubtful accounts		1,775		2,539
Materials and supplies		0		0
Current derivative asset		8,513		12,870
Income taxes receivable		2,405		243
Assets held for sale		0		0
Prepaid expenses and other		1,990		1,993
Total current assets		15,191		18,048
Oil and natural gas properties on the full cost method:
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		9,731		9,273
Other		28,824		28,584
Property, plant, and equipment, gross		38,555		37,857
Less accumulated depreciation, depletion, amortization, and impairment		30,652		27,504
Net property and equipment		7,903		10,353
Intercompany receivable		1,046,308		950,916
Goodwill		0		0
Investments		1,166,768		1,160,444
Operating right of use asset		58
Other assets		8,731		8,225
Total assets		2,244,959		2,147,986
Current liabilities:
Accounts payable		10,892		8,697
Accrued liabilities		22,080		28,230
Current operating lease liability		24
Current portion of other long-term liabilities		1,083		812
Total current liabilities		34,079		37,739
Intercompany debt		0		0
Long-term debt		749,090		644,475
Non-current derivative liability		256		293
Operating lease liability		34
Other long-term liabilities		14,669		13,134
Deferred income taxes		56,471		60,983
Shareholders' equity:
Preferred stock, $1.00 par value, 5,000,000 shares authorized, none issued		0		0
Common stock, $.20 par value, 175,000,000 shares authorized		10,590		10,414
Capital in excess of par value		638,769		628,108
Contributions from Unit		0		0
Accumulated other comprehensive income (loss)		0		0
Retained earnings		741,001		752,840
Total shareholders’ equity attributable to Unit Corporation		1,390,360		1,391,362
Non-controlling interests in consolidated subsidiaries		0		0
Total shareholders' equity		1,390,360		1,391,362
Total liabilities and shareholders' equity		2,244,959		2,147,986
Combined Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents		159		208	254		191
Accounts receivable, net of allowance for doubtful accounts		71,965		94,526
Materials and supplies		516		473
Current derivative asset		0		0
Income taxes receivable		0		1,811
Assets held for sale		19,500		22,511
Prepaid expenses and other		2,931		3,560
Total current assets		95,071		123,089
Oil and natural gas properties on the full cost method:
Proved properties		6,212,323		6,018,568
Unproved properties not being amortized		336,214		330,216
Drilling equipment		1,284,295		1,284,419
Gas gathering and processing equipment		0		0
Saltwater disposal systems		69,212		68,339
Corporate land and building		59,080		59,081
Transportation equipment		17,136		17,165
Other		29,076		28,923
Property, plant, and equipment, gross		8,007,336		7,806,711
Less accumulated depreciation, depletion, amortization, and impairment		5,871,078		5,790,481
Net property and equipment		2,136,258		2,016,230
Intercompany receivable		0		0
Goodwill		62,808		62,808
Investments		0		0
Operating right of use asset		2,080
Other assets		9,802		6,793
Total assets		2,306,019		2,208,920
Current liabilities:
Accounts payable		110,379		122,610
Accrued liabilities		17,837		16,409
Current operating lease liability		925
Current portion of other long-term liabilities		5,834		6,563
Total current liabilities		134,975		145,582
Intercompany debt		1,046,159		948,707
Long-term debt		0		0
Non-current derivative liability		0		0
Operating lease liability		1,122
Other long-term liabilities		77,088		73,713
Deferred income taxes		86,014		83,765
Shareholders' equity:
Preferred stock, $1.00 par value, 5,000,000 shares authorized, none issued		0		0
Common stock, $.20 par value, 175,000,000 shares authorized		0		0
Capital in excess of par value		45,921		45,921
Contributions from Unit		0		0
Accumulated other comprehensive income (loss)		(487)		(481)
Retained earnings		915,227		911,713
Total shareholders’ equity attributable to Unit Corporation		960,661		957,153
Non-controlling interests in consolidated subsidiaries		0		0
Total shareholders' equity		960,661		957,153
Total liabilities and shareholders' equity		2,306,019		2,208,920
Combined Non-Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents		2		5,841	$ 7,002		$ 0
Accounts receivable, net of allowance for doubtful accounts		22,058		36,676
Materials and supplies		0		0
Current derivative asset		0		0
Income taxes receivable		0		0
Assets held for sale		0		0
Prepaid expenses and other		4,185		1,049
Total current assets		26,245		43,566
Oil and natural gas properties on the full cost method:
Proved properties		0		0
Unproved properties not being amortized		0		0
Drilling equipment		0		0
Gas gathering and processing equipment		798,503		767,388
Saltwater disposal systems		0		0
Corporate land and building		0		0
Transportation equipment		3,152		3,086
Other		0		0
Property, plant, and equipment, gross		801,655		770,474
Less accumulated depreciation, depletion, amortization, and impairment		387,845		364,741
Net property and equipment		413,810		405,733
Intercompany receivable		0		0
Goodwill		0		0
Investments		0		0
Operating right of use asset		6,221
Other assets		15,330		17,552
Total assets		461,606		466,851
Current liabilities:
Accounts payable		15,779		32,214
Accrued liabilities		5,725		5,493
Current operating lease liability		3,576
Current portion of other long-term liabilities		6,970		6,875
Total current liabilities		32,050		44,582
Intercompany debt		149		2,209
Long-term debt		7,500		0
Non-current derivative liability		0		0
Operating lease liability		2,451
Other long-term liabilities		11,449		14,687
Deferred income taxes		0		0
Shareholders' equity:
Preferred stock, $1.00 par value, 5,000,000 shares authorized, none issued		0		0
Common stock, $.20 par value, 175,000,000 shares authorized		0		0
Capital in excess of par value		197,042		197,042
Contributions from Unit		1,145		792
Accumulated other comprehensive income (loss)		0		0
Retained earnings		6,461		4,976
Total shareholders’ equity attributable to Unit Corporation		204,648		202,810
Non-controlling interests in consolidated subsidiaries		203,359		202,563
Total shareholders' equity		408,007		405,373
Total liabilities and shareholders' equity		$ 461,606		$ 466,851

[1] Unit Corporation's consolidated total assets as of June 30, 2019 include total current and long-term assets of its variable interest entity (VIE) (Superior Pipeline Company, L.L.C.) of $23.7 million and $435.4 million, respectively, which can only be used to settle obligations of the VIE. Unit Corporation's consolidated total liabilities as of June 30, 2019 include total current and long-term liabilities of the VIE of $29.6 million and $21.4 million, respectively, for which the creditors of the VIE have no recourse to Unit Corporation. Unit Corporation's consolidated total assets as of December 31, 2018 include total current and long-term assets of the VIE of $40.1 million and $423.3 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 total 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 14 – Variable Interest Entity Arrangements.