Variable Interest Entity Arrangements Variable Interest Entity Arrangements (Schedule of Assets and Liabilities) (Details) - USD ($) $ in Thousands	Jun. 30, 2018		Jan. 01, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Variable Interest Entity [Line Items]
Cash and cash equivalents	$ 104,308			$ 701	$ 849	$ 893
Accounts receivable, net of allowance for doubtful accounts	113,377			111,512
Prepaid expenses and other	8,731			6,233
Total current assets	227,044			119,672
Gas gathering and processing equipment	736,488			726,236
Transportation equipment	29,918			29,631
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
Other assets	28,113		$ 27,028	16,230
Total assets	2,749,809	[1]		2,581,452
Accounts payable	114,411			112,648
Accrued liabilities	49,064			48,523
Current portion of other long-term liabilities	14,036		15,750	13,002
Total current liabilities	200,714			181,936
Long-term debt less debt issuance costs	643,371			820,276
Other long-term liabilities	102,928		$ 109,940	$ 100,203
VIE [Member]
Variable Interest Entity [Line Items]
Cash and cash equivalents	7,002
Accounts receivable, net of allowance for doubtful accounts	28,378
Prepaid expenses and other	3,009
Total current assets	38,389
Gas gathering and processing equipment	736,488
Transportation equipment	3,102
Property, plant, and equipment, gross	739,590
Less accumulated depreciation, depletion, amortization, and impairment	342,269
Net property and equipment	397,321
Other assets	14,916
Total assets	450,626
Accounts payable	24,898
Accrued liabilities	2,005
Current portion of other long-term liabilities	6,796
Total current liabilities	33,699
Long-term debt less debt issuance costs	0
Other long-term liabilities	17,856
Total liabilities	$ 51,555

[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,