Summary of Significant Accounting Policies (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Amortizable intangible assets
Gross carrying amount	$ 821,345		$ 821,345
Accumulated amortization	(283,530)		(283,530)
Net carrying amount	537,815		537,815
Amortization expense associated with amortizable intangible assets (including deferred financing costs)	10,404	12,128	33,393	31,335
Customer Relationships and Acquisition Costs
Amortizable intangible assets
Gross carrying amount	749,818		749,818
Accumulated amortization	(261,510)		(261,510)
Net carrying amount	488,308		488,308
Core Technology
Amortizable intangible assets
Gross carrying amount	3,786		3,786
Accumulated amortization	(3,448)		(3,448)
Net carrying amount	338		338
Trademarks and Non-Compete Agreements
Amortizable intangible assets
Gross carrying amount	5,786		5,786
Accumulated amortization	(3,633)		(3,633)
Net carrying amount	2,153		2,153
Deferred Financing Costs
Amortizable intangible assets
Gross carrying amount	61,955		61,955
Accumulated amortization	(14,939)		(14,939)
Net carrying amount	$ 47,016		$ 47,016