Property and Equipment, Net (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property and equipment	$ 198,582		$ 198,582		$ 183,893
Finance leases - right of use asset	715		715		1,299
Less: accumulated depreciation and amortization	(135,484)		(135,484)		(123,314)
Property and equipment, net	63,098		63,098		60,579
Depreciation and amortization expense	6,400	$ 6,300	12,600	$ 12,800
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, net	124,021		124,021		112,599
Computer software
Property, Plant and Equipment [Line Items]
Property and equipment, net	26,241		26,241		26,137
Furniture, fixtures and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, net	8,140		8,140		6,973
Finance leases - right of use asset
Property, Plant and Equipment [Line Items]
Property and equipment, net	3,503		3,503		3,503
Scanner appliances
Property, Plant and Equipment [Line Items]
Property and equipment, net	16,366		16,366		15,864
Scanner appliances and other computer equipment subject to subscription
Property, Plant and Equipment [Line Items]
Property and equipment, net	8,200		8,200		4,900
Scanner appliances and other computer equipment not placed in service
Property, Plant and Equipment [Line Items]
Property and equipment	4,500		4,500		900
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, net	$ 20,311		$ 20,311		$ 18,817