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

Schedule of Stock Activity Related to Share-Based Compensation (Parenthetical) (Detail) (Restricted Stock Units (RSUs))	9 Months Ended
	Sep. 30, 2013
Minimum \| 2014 \| Related to TSR Performance Measurements
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted Stock Units adjustments, percentage	0.00%
Minimum \| 2015 \| Related to TSR Performance Measurements
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted Stock Units adjustments, percentage	0.00%
Minimum \| 2015 \| Related to Company Performance Measurements
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted Stock Units adjustments, percentage	0.00%
Maximum \| 2014 \| Related to TSR Performance Measurements
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted Stock Units adjustments, percentage	150.00%
Maximum \| 2015 \| Related to TSR Performance Measurements
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted Stock Units adjustments, percentage	200.00%
Maximum \| 2015 \| Related to Company Performance Measurements
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted Stock Units adjustments, percentage	150.00%