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

Schedule of Stock Activity Related to Share-Based Compensation (Detail)	12 Months Ended
	Dec. 31, 2012
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards expected to vest by period	43,687
Restricted Stock \| 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards expected to vest by period	24,019
Restricted Stock \| 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards expected to vest by period	12,354
Restricted Stock \| 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards expected to vest by period	7,314
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards expected to vest by period	969,820
Restricted Stock Units (RSUs) \| 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards expected to vest by period	475,689
Restricted Stock Units (RSUs) \| 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards expected to vest by period	494,131