Commitments, Contingencies and Guarantees - Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Minimum Rental Commitments, Capital
2016	$ 9,746
2017	2,652
2018	628
Total minimum lease payments	13,026
Minimum Rental Commitments, Operating
2016	9,526
2017	8,532
2018	7,484
2019	5,891
2020	4,789
Thereafter	601
Total minimum lease payments	36,823
Operating lease expense, net of amortization expense related to landlord incentives	5,300	$ 3,500	$ 4,300
Occupancy lease expense	3,900	1,700	1,900
Communication equipment lease expense	$ 1,400	$ 1,800	$ 2,400