Business Combination - Activity - CBR (Details) - USD ($) $ in Thousands		3 Months Ended	6 Months Ended
	Aug. 17, 2015	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Goodwill			$ 639,484		$ 639,188
Other disclosures
Net deferred tax liability			188,852		$ 189,145
Acquisition-related costs		$ 2,653		$ 2,653
CBR Acquisition Holdings Corp
Business Combinations
Cash consideration	$ 700,000
Estimated working capital and other adjustments	(17,837)
Purchase price paid at closing	682,163
Cash paid on finalization of net working capital, indebtedness and other adjustments	193
Total purchase price	682,356
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Accounts receivable	8,660
Inventories	3,825
Prepaid and other current assets	8,480
Restricted cash - short-term	30,752
Property, plant and equipment	29,401
Deferred income tax assets	5,062
Other long-term assets	496
Accounts payable	(2,853)
Accrued expenses	(13,770)
Deferred revenues - short-term	(3,100)
Payable to former CBR shareholders	(37,947)
Deferred income tax liabilities	(149,873)
Other long-term liabilities	(506)
Total estimated identifiable net assets	240,985
Goodwill	441,371		441,400
Total	682,356
Measurement period adjustments
Increase in goodwill due to measurement period adjustments			300
Other disclosures
Contractual amount of accounts receivable	11,700
Contractual amount of accounts receivable expected to be collectible	8,700
Net deferred tax liability			$ 144,800
Combined federal and state statutory income tax rate (as a percent)			37.00%
CBR Acquisition Holdings Corp | CBR customer relationships
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Finite-lived intangible assets	$ 297,000
Other disclosures
Useful life	20 years		20 years
CBR Acquisition Holdings Corp | Favorable lease
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Finite-lived intangible assets	$ 358
CBR Trade Names and Trademarks | CBR Acquisition Holdings Corp
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Indefinite-lived intangible assets	$ 65,000