Long-Lived Assets - Summary of Carrying Value of Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 259,637	$ 267,141
Accumulated Amortization	(192,658)	(196,039)
Net Amount	66,979	71,102
Client contracts
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	126,495	137,398
Accumulated Amortization	(88,406)	(96,723)
Net Amount	38,089	40,675
Software
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	133,142	129,743
Accumulated Amortization	(104,252)	(99,316)
Net Amount	$ 28,890	$ 30,427