Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 57,522	$ 57,669
Less accumulated depreciation and amortization	(15,818)	(20,608)
Property and equipment, net	41,704	37,061
Depreciation expense	3,800	4,000	$ 3,500
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	11,051	17,957
Buildings
Property, Plant and Equipment [Line Items]
Property and equipment, gross	23,749	22,607
Land
Property, Plant and Equipment [Line Items]
Property and equipment, gross	5,930	7,986
Land Improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	6,906	0
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,435	1,465
Furniture, fixtures and other
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 8,451	$ 7,654