Property and Equipment, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment	$ 183,893	$ 160,672
Finance Lease, Right-of-Use Asset	1,299
Less: accumulated depreciation and amortization	(123,314)	(99,230)
Property and equipment, net	60,579	61,442
Depreciation	24,900	25,100	$ 19,900
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment	112,599	93,530
Computer software
Property, Plant and Equipment [Line Items]
Property and equipment	26,137	26,030
Furniture, fixtures and equipment
Property, Plant and Equipment [Line Items]
Property and equipment	6,973	5,814
Equipment Under Capital Lease [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	3,503
Finance Lease, Right-of-Use Asset		3,503
Scanner appliances
Property, Plant and Equipment [Line Items]
Property and equipment	15,864	15,356
Scanner appliances and other computer equipment subject to subscription
Property, Plant and Equipment [Line Items]
Property and equipment, net	4,900	7,900
Scanner appliances and other computer equipment not placed in service
Property, Plant and Equipment [Line Items]
Property and equipment	900	1,800
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment	$ 18,817	$ 16,439