Document and Entity Information Document and Entity Information	12 Months Ended
	Dec. 31, 2020
Document And Entity Information [Abstract]
Document Type	10-K/A
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Document Transition Report	false
Entity File Number	1-9260
Entity Registrant Name	UNIT CORPORATION
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	73-1283193
Entity Address, Address Line One	8200 South Unit Drive,
Entity Address, City or Town	Tulsa,
Entity Address, State or Province	OK
Entity Address, Country	US
Entity Address, Postal Zip Code	74132
City Area Code	(918)
Local Phone Number	493-7700
Title of 12(b) Security	N/A
Trading Symbol	N/A
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	Yes
Entity Current Reporting Status	No
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Amendment Flag	true
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Entity Central Index Key	0000798949
Current Fiscal Year End Date	--12-31
Entity Bankruptcy Proceedings, Reporting Current	true
Amendment Description	On May 22, 2020, Unit Corporation ("Company") and its wholly owned subsidiaries, Unit Petroleum Company ("UPC"), Unit Drilling Company ("UDC"), 8200 Unit Drive, L.L.C. ("8200 Unit"), Unit Drilling Colombia, L.L.C. ("Unit Drilling Colombia") and Unit Drilling USA Colombia, L.L.C. ("Unit Drilling USA" and together with the Company, UPC, UDC, 8200 Unit and Unit Drilling Colombia, the "Debtors") filed voluntary petitions for relief under Chapter 11 of Title 11 of the United States Code ("Bankruptcy Code") with the United States Bankruptcy Court for the Southern District of Texas, Houston Division ("Bankruptcy Court"). The Debtors’ Chapter 11 cases ("Chapter 11 Cases") were jointly administered under the caption In re Unit Corporation, et al., Case No. 20-32740 (DRJ).In connection with the Chapter 11 Cases, on August 6, 2020, the Bankruptcy Court entered an order, Docket No. 340 (Confirmation Order), confirming the Debtors’ Amended Joint Chapter 11 Plan of Reorganization [Docket No. 320] (as amended, supplemented and modified, "the Plan"). On September 3, 2020 ("Effective Date"), the conditions to effectiveness of the Plan were satisfied and the Debtors emerged from the Chapter 11 Cases. Unit Corporation (the "company," "Unit," "us," "our," or "we") is filing this Amendment No. 1 on Form 10-K/A (this "Amendment No. 1") to its original Annual Report on Form 10-K for the fiscal year ended December 31, 2020 filed with the U. S. Securities and Exchange Commission (the "SEC") on March 31, 2021 (the "Original Form 10-K") for the sole purpose of including information required in Part III of Form 10-K. The information was previously omitted from the Original Form 10-K in reliance on General Instruction G(3) of Form 10-K, which permits Part III information to be incorporated by reference from a definitive proxy statement, if the definitive proxy statement is filed no later than 120 days after the end of the fiscal year. The company is filing this Amendment No. 1 to include its Part III information because we no longer intend to file our definitive proxy statement within 120 days of December 31, 2020.In addition to including the information required in Part III of Form 10-K, this Amendment No. 1 also amends and restates Item 15 of Part IV of the Original Form 10-K to include as exhibits certifications required by Rule 13a-14(a) under the Securities Exchange Act of 1934, as amended. The information in this Amendment No. 1 is supplemental to and does not otherwise update any other information provided in the Original Form 10-K. This Amendment No. 1 does not reflect events that may have occurred subsequent to the filing date of our Original Form 10-K. Among other things, forward-looking statements made in the Original Form 10-K have not been revised to reflect events, results, or developments that have occurred or facts that have become known to us after the date of the Original Form 10-K, and such forward-looking statements should be read in their historical context. Accordingly, this Amendment No. 1 should be read in conjunction with our filings made with the SEC subsequent to the filing of the Original Form 10-K.