Goodwill and Identifiable Intangible Assets - Schedule of Finite-lived and Indefinite-lived Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Schedule of Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Accumulated Amortization	$ (252,164)	$ (214,269)
Total	348,232
Gross Carrying Amount, Trade names (unamortized)	174,039	170,218
Accumulated Impairment Charge, Trade names (unamortized)	(49,437)	(49,437)
Total, Trade names (unamortized)	124,602	120,781
Gross Carrying Amount, Total	779,269	770,600
Accumulated Impairment Charge, Total	(54,271)	(54,271)
Total	472,834	502,060
Contract backlog
Schedule of Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	47,745	47,620
Accumulated Amortization	(47,745)	(47,620)
Accumulated Impairment Charge	0	0
Total	0	0
Developed technology/Vendor network
Schedule of Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	95,661	95,661
Accumulated Amortization	(40,482)	(35,347)
Accumulated Impairment Charge	0	0
Total	55,179	60,314
Customer relationships
Schedule of Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	430,356	425,873
Accumulated Amortization	(141,695)	(112,457)
Accumulated Impairment Charge	(4,834)	(4,834)
Total	283,827	308,582
Non-competition agreements
Schedule of Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	10,220	9,980
Accumulated Amortization	(9,832)	(9,330)
Accumulated Impairment Charge	0	0
Total	388	650
Trade names (amortized)
Schedule of Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	21,248	21,248
Accumulated Amortization	(12,410)	(9,515)
Accumulated Impairment Charge	0	0
Total	$ 8,838	$ 11,733