Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property Plant And Equipment [Line Items]
Assets under capital leases	$ 200	$ 1,400
Accumulated depreciation - assets under capital leases		900
Depreciation	14,612	13,843	$ 11,737
Accumulated depreciation	72,119	59,929
Internally developed software
Property Plant And Equipment [Line Items]
Depreciation	5,400	5,200	4,500
Accumulated depreciation	34,500	29,400
Impairment loss on internally developed software	$ 400	$ 900	$ 800