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

Fair Value Measurements - Schedule of Fair Value of Long-Term Debt (Details) - Fair Value, Inputs, Level 2 - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
11.00% 1.5 Lien Term Loan, Due November 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Long-term debt, term loan fair value	$ 75,000	$ 75,000
9.00 % Second Lien Term Loan, Due May 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Long-term debt, term loan fair value	303,000	288,000
9.00%/10.75% Second Lien PIK Toggle Notes, Due May 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Long-term debt, notes fair value	179,289	162,322
8.50%/10.00% Third Lien PIK Toggle Notes, Due June 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Long-term debt, notes fair value	165,677	119,490
8.50% Unsecured Senior Notes, Due June 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Long-term debt, notes fair value	$ 188,880	$ 178,439