Long Lived Assets (Details 3) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Client contracts
Summary of aggregate amortization
Total amortization expense	$ 19,367	$ 23,545	$ 28,780
Client contracts | Investments in client contracts
Summary of aggregate amortization
Total amortization expense	6,409	6,181	7,591
Client contracts | Capitalized costs
Summary of aggregate amortization
Total amortization expense	1,007	2,365	4,172
Client contracts | Acquired client contracts
Summary of aggregate amortization
Total amortization expense	11,951	14,999	17,017
Software
Summary of aggregate amortization
Total amortization expense	11,861	11,854	12,685
Software | Acquired software
Summary of aggregate amortization
Total amortization expense	3,457	4,221	5,700
Software | Internal use software
Summary of aggregate amortization
Total amortization expense	$ 8,404	$ 7,633	$ 6,985