Goodwill and Identifiable Intangible Assets - Schedule of Finite-lived and Indefinite-lived Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Schedule of Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Accumulated Amortization	$ (145,275)	$ (115,513)
Total	278,605
Gross Carrying Amount, Trade names (unamortized)	113,109	112,601
Accumulated Impairment Charge, Trade names (unamortized)	(47,966)	(47,966)
Total, Trade names (unamortized)	65,143	64,635
Gross Carrying Amount, Total	541,823	538,686
Accumulated Impairment Charge, Total	(52,800)	(52,800)
Total	343,748	370,373
Contract backlog
Schedule of Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	47,580	47,580
Accumulated Amortization	(46,630)	(41,505)
Accumulated Impairment Charge	0	0
Total	950	6,075
Developed technology/Vendor network
Schedule of Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	95,661	95,661
Accumulated Amortization	(25,078)	(19,943)
Accumulated Impairment Charge	0	0
Total	70,583	75,718
Customer relationships
Schedule of Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	259,683	257,054
Accumulated Amortization	(61,718)	(45,213)
Accumulated Impairment Charge	(4,834)	(4,834)
Total	193,131	207,007
Non-competition agreements
Schedule of Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	8,269	8,269
Accumulated Amortization	(7,898)	(7,386)
Accumulated Impairment Charge	0	0
Total	371	883
Trade names (amortized)
Schedule of Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	17,521	17,521
Accumulated Amortization	(3,951)	(1,466)
Accumulated Impairment Charge	0	0
Total	$ 13,570	$ 16,055