Supplemental Condensed Consolidated Financial Information (Condensed Consolidating Balance Sheets) (Details) - USD ($) $ in Thousands	Jun. 30, 2018		Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 104,308				$ 701	$ 849		$ 893
Accounts receivable, net of allowance for doubtful accounts	113,377				111,512
Materials and supplies	501				505
Current derivative asset	127				721
Prepaid expenses and other	8,731				6,233
Total current assets	227,044				119,672
Oil and natural gas properties on the full cost method:
Proved properties	5,809,850				5,712,813
Unproved properties not being amortized	325,595				296,764
Drilling equipment	1,612,817				1,593,611
Gas gathering and processing equipment	736,488				726,236
Saltwater disposal systems	65,218				62,618
Corporate land and building	59,081				59,080
Transportation equipment	29,918				29,631
Other	56,381				53,439
Property, plant, and equipment, gross	8,695,348				8,534,192
Less accumulated depreciation, depletion, amortization, and impairment	6,263,504				6,151,450
Net property and equipment	2,431,844				2,382,742
Intercompany receivable	0				0
Goodwill	62,808				62,808
Investments	1,500				1,500
Other assets	26,613				14,730
Total assets	2,749,809	[1]			2,581,452
Current liabilities:
Accounts payable	114,411				112,648
Accrued liabilities	49,064				48,523
Income taxes payable	4,648				0
Current derivative liability	18,555				7,763
Current portion of other long-term liabilities	14,036			$ 15,750	13,002
Total current liabilities	200,714				181,936
Intercompany debt	0				0
Long-term debt					178,000
Bonds payable less debt issuance costs	643,371				642,276
Non-current derivative liability	910				0
Other long-term liabilities	102,928			109,940	100,203
Deferred income taxes	158,232			133,064	133,477
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, 54,089,366 shares issued	10,414				10,280
Capital in excess of par value	622,120				535,815
Accumulated other comprehensive income (loss)	(65)		$ (100)	63	63	20	$ 0	0
Retained earnings	811,781			$ 798,128	799,402
Total Unit Corporation shareholders’ equity	1,444,250				1,345,560
Non-controlling interests in consolidated subsidiaries	199,404				0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	1,643,654				1,345,560	1,244,463		1,194,070
Total liabilities and shareholders' equity	2,749,809	[1]			2,581,452
Consolidating Adjustments [Member]
Current assets:
Cash and cash equivalents	0				0	0		0
Accounts receivable, net of allowance for doubtful accounts	0				0
Materials and supplies	0				0
Current derivative asset	0				0
Prepaid expenses and other	0				0
Total current assets	0				0
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	(877,823)				(1,155,725)
Goodwill	0				0
Investments	(1,216,959)				(1,044,709)
Other assets	0				0
Total assets	(2,094,782)				(2,200,434)
Current liabilities:
Accounts payable	0				0
Accrued liabilities	0				0
Income taxes payable	0
Current derivative liability	0				0
Current portion of other long-term liabilities	0				0
Total current liabilities	0				0
Intercompany debt	(877,823)				(1,155,725)
Long-term debt					0
Bonds payable less debt issuance costs	0				0
Non-current derivative liability	0
Other long-term liabilities	0				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, $.20 par value, 175,000,000 shares authorized, 54,089,366 shares issued	0				0
Capital in excess of par value	(242,963)				(61,470)
Accumulated other comprehensive income (loss)	0				0
Retained earnings	(973,996)				(983,239)
Total Unit Corporation shareholders’ equity	(1,216,959)				(1,044,709)
Non-controlling interests in consolidated subsidiaries	0				0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	(1,216,959)				(1,044,709)
Total liabilities and shareholders' equity	(2,094,782)				(2,200,434)
Parent [Member]
Current assets:
Cash and cash equivalents	97,052				510	522		517
Accounts receivable, net of allowance for doubtful accounts	885				154
Materials and supplies	0				0
Current derivative asset	127				721
Prepaid expenses and other	2,643				2,986
Total current assets	100,707				4,371
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	9,244				9,270
Other	28,246				28,039
Property, plant, and equipment, gross	37,490				37,309
Less accumulated depreciation, depletion, amortization, and impairment	24,335				21,268
Net property and equipment	13,155				16,041
Intercompany receivable	877,823				1,155,725
Goodwill	0				0
Investments	1,216,959				1,044,709
Other assets	5,472				5,373
Total assets	2,214,116				2,226,219
Current liabilities:
Accounts payable	9,669				13,124
Accrued liabilities	21,618				26,165
Income taxes payable	4,648
Current derivative liability	18,555				7,763
Current portion of other long-term liabilities	615				657
Total current liabilities	55,105				47,709
Intercompany debt	0				0
Long-term debt					178,000
Bonds payable less debt issuance costs	643,371				642,276
Non-current derivative liability	910
Other long-term liabilities	12,613				11,257
Deferred income taxes	57,802				1,480
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, 54,089,366 shares issued	10,414				10,280
Capital in excess of par value	622,120				535,815
Accumulated other comprehensive income (loss)	0				0
Retained earnings	811,781				799,402
Total Unit Corporation shareholders’ equity	1,444,315				1,345,497
Non-controlling interests in consolidated subsidiaries	0				0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	1,444,315				1,345,497
Total liabilities and shareholders' equity	2,214,116				2,226,219
Combined Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	254				191	327		376
Accounts receivable, net of allowance for doubtful accounts	84,851				83,442
Materials and supplies	501				505
Current derivative asset	0				0
Prepaid expenses and other	3,079				2,370
Total current assets	88,685				86,508
Oil and natural gas properties on the full cost method:
Proved properties	5,809,850				5,712,813
Unproved properties not being amortized	325,595				296,764
Drilling equipment	1,612,817				1,593,611
Gas gathering and processing equipment	0				0
Saltwater disposal systems	65,218				62,618
Corporate land and building	59,081				59,080
Transportation equipment	17,572				17,423
Other	28,135				25,400
Property, plant, and equipment, gross	7,918,268				7,767,709
Less accumulated depreciation, depletion, amortization, and impairment	5,896,900				5,807,757
Net property and equipment	2,021,368				1,959,952
Intercompany receivable	0				0
Goodwill	62,808				62,808
Investments	1,500				1,500
Other assets	6,225				6,328
Total assets	2,180,586				2,117,096
Current liabilities:
Accounts payable	81,827				81,334
Accrued liabilities	24,880				19,134
Income taxes payable	0
Current derivative liability	0				0
Current portion of other long-term liabilities	6,625				8,501
Total current liabilities	113,332				108,969
Intercompany debt	876,277				870,582
Long-term debt					0
Bonds payable less debt issuance costs	0				0
Non-current derivative liability	0
Other long-term liabilities	72,459				77,566
Deferred income taxes	100,430				85,443
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, 54,089,366 shares issued	0				0
Capital in excess of par value	45,921				45,921
Accumulated other comprehensive income (loss)	(65)				63
Retained earnings	972,232				928,552
Total Unit Corporation shareholders’ equity	1,018,088				974,536
Non-controlling interests in consolidated subsidiaries	0				0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	1,018,088				974,536
Total liabilities and shareholders' equity	2,180,586				2,117,096
Combined Non-Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	7,002				0	$ 0		$ 0
Accounts receivable, net of allowance for doubtful accounts	27,641				27,916
Materials and supplies	0				0
Current derivative asset	0				0
Prepaid expenses and other	3,009				877
Total current assets	37,652				28,793
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	736,488				726,236
Saltwater disposal systems	0				0
Corporate land and building	0				0
Transportation equipment	3,102				2,938
Other	0				0
Property, plant, and equipment, gross	739,590				729,174
Less accumulated depreciation, depletion, amortization, and impairment	342,269				322,425
Net property and equipment	397,321				406,749
Intercompany receivable	0				0
Goodwill	0				0
Investments	0				0
Other assets	14,916				3,029
Total assets	449,889				438,571
Current liabilities:
Accounts payable	22,915				18,190
Accrued liabilities	2,566				3,224
Income taxes payable	0
Current derivative liability	0				0
Current portion of other long-term liabilities	6,796				3,844
Total current liabilities	32,277				25,258
Intercompany debt	1,546				285,143
Long-term debt					0
Bonds payable less debt issuance costs	0				0
Non-current derivative liability	0
Other long-term liabilities	17,856				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, $.20 par value, 175,000,000 shares authorized, 54,089,366 shares issued	0				0
Capital in excess of par value	197,042				15,549
Accumulated other comprehensive income (loss)	0				0
Retained earnings	1,764				54,687
Total Unit Corporation shareholders’ equity	198,806				70,236
Non-controlling interests in consolidated subsidiaries	199,404				0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	398,210				70,236
Total liabilities and shareholders' equity	$ 449,889				$ 438,571

[1] Unit Corporation's consolidated total assets as of June 30, 2018 include total current and long-term assets of the variable interest entity (VIE) of $38.4 million and $412.2 million, respectively, which can only be used to settle obligations of the VIE. Unit Corporation's consolidated total liabilities as of June 30, 2018 include total current and long-term liabilities of the VIE of $33.7 million and $17.9 million, respectively,