Quarterly report pursuant to Section 13 or 15(d)

Acquisitions and Divestitures - Additional Information (Details)

v2.4.1.9
Acquisitions and Divestitures - Additional Information (Details) (USD $)
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Sep. 15, 2014
Sep. 14, 2014
May 20, 2014
Business Acquisition [Line Items]          
Revenues $ 127,907,000us-gaap_Revenues $ 254,516,000us-gaap_Revenues      
DD&A 125,467,000us-gaap_DepreciationAmortizationAndAccretionNet 123,306,000us-gaap_DepreciationAmortizationAndAccretionNet      
Income tax expense (benefit) (103,574,000)us-gaap_IncomeTaxExpenseBenefit 6,648,000us-gaap_IncomeTaxExpenseBenefit      
Net income (loss) (255,095,000)us-gaap_NetIncomeLoss 11,189,000us-gaap_NetIncomeLoss      
Fairway          
Business Acquisition [Line Items]          
Percentage of working interest     100.00%wti_PercentageOfWorkingInterest
/ us-gaap_BusinessAcquisitionAxis
= wti_FairwayPropertiesMember
64.30%wti_PercentageOfWorkingInterest
/ us-gaap_BusinessAcquisitionAxis
= wti_FairwayPropertiesMember
 
Adjustments to purchase price 1,300,000us-gaap_PaymentsForPreviousAcquisition
/ us-gaap_BusinessAcquisitionAxis
= wti_FairwayPropertiesMember
       
Goodwill, acquired during period 0us-gaap_GoodwillAcquiredDuringPeriod
/ us-gaap_BusinessAcquisitionAxis
= wti_FairwayPropertiesMember
       
Woodside Properties          
Business Acquisition [Line Items]          
Percentage of working interest         20.00%wti_PercentageOfWorkingInterest
/ us-gaap_BusinessAcquisitionAxis
= wti_WoodsidePropertiesMember
Goodwill, acquired during period 0us-gaap_GoodwillAcquiredDuringPeriod
/ us-gaap_BusinessAcquisitionAxis
= wti_WoodsidePropertiesMember
       
Revenues 5,500,000us-gaap_Revenues
/ us-gaap_BusinessAcquisitionAxis
= wti_WoodsidePropertiesMember
       
Direct operating expenses 3,200,000us-gaap_OperatingCostsAndExpenses
/ us-gaap_BusinessAcquisitionAxis
= wti_WoodsidePropertiesMember
       
DD&A 4,100,000us-gaap_DepreciationAmortizationAndAccretionNet
/ us-gaap_BusinessAcquisitionAxis
= wti_WoodsidePropertiesMember
       
Income tax expense (benefit) 600,000us-gaap_IncomeTaxExpenseBenefit
/ us-gaap_BusinessAcquisitionAxis
= wti_WoodsidePropertiesMember
       
Net income (loss) $ (1,200,000)us-gaap_NetIncomeLoss
/ us-gaap_BusinessAcquisitionAxis
= wti_WoodsidePropertiesMember