Fixed Assets - Asset Retirement Obligation (Details) - USD ($) $ in Thousands		9 Months Ended
	Jul. 24, 2015	Sep. 30, 2015
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO liability balance, December 31, 2014		$ 14,790
AROs arising from the Enterprise acquisition		158,133
AROs from the consolidation of historical interests in CHOPS and SEKCO		1,988
Accretion Expense		2,781
Settlements		(384)
ARO liability balance, September 30, 2015		$ 177,308
Enterprise Offshore Acquisition
Business Acquisition [Line Items]
Effective date of acquisition	Jul. 24, 2015