Quarterly report pursuant to Section 13 or 15(d)

Asset Retirement Obligations - Summary of Changes to Asset Retirement Obligation (Details)

v3.7.0.1
Asset Retirement Obligations - Summary of Changes to Asset Retirement Obligation (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2017
Mar. 31, 2016
Dec. 31, 2016
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]      
Asset retirement obligations, beginning of period $ 334,438    
Asset retirement obligation settlements (14,499) $ (3,180)  
Accretion of discount 4,201    
Revisions of estimated liabilities [1] 2,660    
Asset retirement obligations, end of period 326,800    
Less current portion 66,150   $ 78,264
Long-term $ 260,650   $ 256,174
[1] Revisions were primarily related to changes in scope of work at both our West Cameron fields and Eugene Island fields.