Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 57,669	$ 50,142
Less accumulated depreciation and amortization	(20,608)	(16,054)
Property and equipment, net	37,061	34,088
Depreciation expense	4,000	3,500	$ 2,300
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	17,957	15,318
Buildings
Property, Plant and Equipment [Line Items]
Property and equipment, gross	22,607	20,741
Land
Property, Plant and Equipment [Line Items]
Property and equipment, gross	7,986	6,545
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,465	1,239
Furniture, fixtures and other
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 7,654	$ 6,299