Summary of Significant Accounting Policies Summary of Significant Accounting Policies - Schedule of Components of Amortizable Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Amortizable intangible assets
Gross carrying amount	$ 987,650		$ 987,650		$ 978,529
Accumulated amortization	(346,533)		(346,533)		(321,593)
Net carrying amount	641,117		641,117		656,936
Amortization of other deferred charges	13,593	$ 14,332	26,845	$ 27,958
Customer Relationships and Acquisition Costs
Amortizable intangible assets
Gross carrying amount	913,523		913,523		904,866
Accumulated amortization	(318,055)		(318,055)		(297,029)
Net carrying amount	595,468		595,468		607,837
Core Technology
Amortizable intangible assets
Gross carrying amount	3,414		3,414		3,568
Accumulated amortization	(3,414)		(3,414)		(3,540)
Net carrying amount	0		0		28
Trademarks and Non-Compete Agreements
Amortizable intangible assets
Gross carrying amount	6,908		6,908		7,062
Accumulated amortization	(5,086)		(5,086)		(5,068)
Net carrying amount	1,822		1,822		1,994
Deferred Financing Costs
Amortizable intangible assets
Gross carrying amount	63,805		63,805		63,033
Accumulated amortization	(19,978)		(19,978)		(15,956)
Net carrying amount	$ 43,827		$ 43,827		$ 47,077