W&T Offshore, Inc. Annual report pursuant to Section 13 and 15(d)

Selected Quarterly Financial Data (Parenthetical) (Details) - USD ($) $ in Thousands, shares in Millions		3 Months Ended			12 Months Ended
	Sep. 07, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Data [Line Items]
Ceiling test write-down of oil and natural gas properties		$ 57,900	$ 104,600	$ 116,600	$ 0	$ 279,063	$ 987,238
Gain on exchange of debt		$ 123,900			$ 7,811	123,923
Exchange Transaction
Quarterly Financial Data [Line Items]
Gain on exchange of debt						$ 123,900
Exchange Transaction \| Common Stock
Quarterly Financial Data [Line Items]
Debt conversion, common stock shares issued	60.4	60.4