Business Combinations - Narrative - CBR Acquisition (Details) - USD ($) $ in Thousands		1 Months Ended	9 Months Ended
	Aug. 17, 2015	Aug. 31, 2015	Sep. 30, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Net deferred tax liability			$ 192,608	$ 189,145
CBR
Business Acquisition [Line Items]
Cash consideration	$ 700,000
Increase in goodwill			$ 300
Gross contractual amount of accounts receivable	11,700
Fair value accounts receivable	8,660
Net deferred tax liability	$ 144,800
Combined federal and state statutory income tax rate (as a percent)	37.00%
Deferred tax liabilities	$ 149,873
Deferred tax assets	$ 5,062
CBR | Customer relationships
Business Acquisition [Line Items]
Expected useful life (in years)		20 years	20 years