Supplemental Condensed Consolidated Financial Information (Condensed Consolidating Balance Sheets) (Details) - USD ($) $ in Thousands		Sep. 30, 2020	Sep. 01, 2020	Aug. 31, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents		$ 29,784		$ 32,940			$ 571	$ 612			$ 6,452
Accounts receivable, net of allowance for doubtful accounts		52,824					82,656
Materials and supplies		0					449
Current derivative asset		2,367					633
Current income taxes receivable		850					1,756
Assets held for sale		0					5,908
Prepaid expenses and other		12,531					13,078
Total current assets		105,814					105,051
Oil and natural gas properties on the full cost method:
Proved properties		238,766	$ 238,284	6,539,816			6,341,582
Unproved properties not being amortized		735	0	30,205			252,874
Drilling equipment		63,541	63,458	1,285,024			1,295,713
Gas gathering and processing equipment		250,608	250,098	833,788			824,699
Saltwater disposal systems		0	0	43,541			69,692
Land and building		32,635	32,635	59,080			59,080
Transportation equipment		3,291	3,314	15,577			29,723
Other		9,961	9,958	57,427			57,992
Property, plant, and equipment, gross		599,537					8,931,355
Less accumulated depreciation, depletion, amortization, and impairment		20,907					6,978,669
Net property and equipment		578,630					1,952,686
Intercompany receivable							0
Investments							0
Operating right of use asset		6,488					5,673
Other assets		17,628					26,642
Total assets	[1]	708,560					2,090,052
Current liabilities:
Accounts payable		37,307					84,481
Accrued liabilities		28,175					46,562
Current operating lease liability		3,985					3,430
Current portion of long-term debt		400					108,200
Current derivative liability		1,114					0
Current portion of other long-term liabilities		12,324					17,376
Total current liabilities		84,190					260,049
Intercompany debt							0
Long-term debt		143,600					663,216
Non-current derivative liability		1,749					27
Operating lease liability		2,431					2,071
Liabilities subject to compromise			762,215
Deferred income taxes		0					13,713
Total shareholders' equity		432,800	$ 439,523	171,180	$ 40,532	$ 254,486	1,055,635	1,391,233	$ 1,593,232	$ 1,595,859	1,593,444
Total liabilities and shareholders' equity	[1]	708,560					2,090,052
Total other long-term liabilities		$ 43,790					95,341
Consolidating Adjustments [Member]
Current assets:
Cash and cash equivalents				0			0	0			0
Accounts receivable, net of allowance for doubtful accounts							(9,447)
Materials and supplies							0
Current derivative asset							0
Current income taxes receivable							0
Assets held for sale							0
Prepaid expenses and other							0
Total current assets							(9,447)
Oil and natural gas properties on the full cost method:
Proved properties							0
Unproved properties not being amortized							0
Drilling equipment							0
Gas gathering and processing equipment							0
Saltwater disposal systems							0
Land and building							0
Transportation equipment							0
Other							0
Property, plant, and equipment, gross							0
Less accumulated depreciation, depletion, amortization, and impairment							0
Net property and equipment							0
Intercompany receivable							(1,048,785)
Investments							(865,252)
Operating right of use asset							(54)
Other assets							0
Total assets							(1,923,538)
Current liabilities:
Accounts payable							(7,291)
Accrued liabilities							(2,156)
Current operating lease liability							(6)
Current portion of long-term debt							0
Current portion of other long-term liabilities							0
Total current liabilities							(9,453)
Intercompany debt							(1,048,785)
Long-term debt							0
Non-current derivative liability							0
Operating lease liability							(48)
Deferred income taxes							0
Total shareholders' equity							(865,252)
Total liabilities and shareholders' equity							(1,923,538)
Total other long-term liabilities							0
Parent [Member]
Current assets:
Cash and cash equivalents				15,764			503	505			403
Accounts receivable, net of allowance for doubtful accounts							2,645
Materials and supplies							0
Current derivative asset							633
Current income taxes receivable							1,756
Assets held for sale							0
Prepaid expenses and other							2,019
Total current assets							7,556
Oil and natural gas properties on the full cost method:
Proved properties							0
Unproved properties not being amortized							0
Drilling equipment							0
Gas gathering and processing equipment							0
Saltwater disposal systems							0
Land and building							0
Transportation equipment							9,712
Other							28,927
Property, plant, and equipment, gross							38,639
Less accumulated depreciation, depletion, amortization, and impairment							33,794
Net property and equipment							4,845
Intercompany receivable							1,048,785
Investments							865,252
Operating right of use asset							46
Other assets							8,107
Total assets							1,934,591
Current liabilities:
Accounts payable							12,259
Accrued liabilities							28,003
Current operating lease liability							20
Current portion of long-term debt							108,200
Current portion of other long-term liabilities							3,003
Total current liabilities							151,485
Intercompany debt							0
Long-term debt							646,716
Non-current derivative liability							27
Operating lease liability							25
Deferred income taxes							68,150
Total shareholders' equity							1,055,635
Total liabilities and shareholders' equity							1,934,591
Total other long-term liabilities							12,553
Combined Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents				0			68	104			208
Accounts receivable, net of allowance for doubtful accounts							64,805
Materials and supplies							449
Current derivative asset							0
Current income taxes receivable							0
Assets held for sale							5,908
Prepaid expenses and other							3,373
Total current assets							74,603
Oil and natural gas properties on the full cost method:
Proved properties							6,341,582
Unproved properties not being amortized							252,874
Drilling equipment							1,295,713
Gas gathering and processing equipment							0
Saltwater disposal systems							69,692
Land and building							59,080
Transportation equipment							16,621
Other							29,065
Property, plant, and equipment, gross							8,064,627
Less accumulated depreciation, depletion, amortization, and impairment							6,537,731
Net property and equipment							1,526,896
Intercompany receivable							0
Investments							0
Operating right of use asset							1,733
Other assets							9,094
Total assets							1,612,326
Current liabilities:
Accounts payable							61,002
Accrued liabilities							14,024
Current operating lease liability							1,009
Current portion of long-term debt							0
Current portion of other long-term liabilities							7,313
Total current liabilities							83,348
Intercompany debt							1,047,599
Long-term debt							0
Non-current derivative liability							0
Operating lease liability							690
Deferred income taxes							(54,437)
Total shareholders' equity							460,464
Total liabilities and shareholders' equity							1,612,326
Total other long-term liabilities							74,662
Combined Non-Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents				$ 17,176			0	$ 3			$ 5,841
Accounts receivable, net of allowance for doubtful accounts							24,653
Materials and supplies							0
Current derivative asset							0
Current income taxes receivable							0
Assets held for sale							0
Prepaid expenses and other							7,686
Total current assets							32,339
Oil and natural gas properties on the full cost method:
Proved properties							0
Unproved properties not being amortized							0
Drilling equipment							0
Gas gathering and processing equipment							824,699
Saltwater disposal systems							0
Land and building							0
Transportation equipment							3,390
Other							0
Property, plant, and equipment, gross							828,089
Less accumulated depreciation, depletion, amortization, and impairment							407,144
Net property and equipment							420,945
Intercompany receivable							0
Investments							0
Operating right of use asset							3,948
Other assets							9,441
Total assets							466,673
Current liabilities:
Accounts payable							18,511
Accrued liabilities							6,691
Current operating lease liability							2,407
Current portion of long-term debt							0
Current portion of other long-term liabilities							7,060
Total current liabilities							34,669
Intercompany debt							1,186
Long-term debt							16,500
Non-current derivative liability							0
Operating lease liability							1,404
Deferred income taxes							0
Total shareholders' equity							404,788
Total liabilities and shareholders' equity							466,673
Total other long-term liabilities							$ 8,126

[1] Unit Corporation's consolidated total assets as of September 30, 2020 include total current and long-term assets of its variable interest entity (VIE) (Superior Pipeline Company, L.L.C.) of $45.9 million and $257.0 million, respectively, which can only settle obligations of the VIE. Unit Corporation's consolidated total liabilities as of September 30, 2020 include total current and long-term liabilities of the VIE of $26.5 million and $15.6 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, 2019 include total current and long-term assets of the VIE of $28.8 million and $434.3 million, respectively, which can only settle obligations of the VIE. Unit Corporation's consolidated total liabilities as of December 31, 2019 include total current and long-term liabilities of the VIE of $32.2 million and $26.0 million, respectively, for which the creditors of the VIE have no recourse to Unit Corporation. See Note 17 – Variable Interest Entity Arrangements.