Business Combinations - Additional Information (Details) - USD ($)				3 Months Ended	9 Months Ended
	Sep. 30, 2017	Jan. 27, 2017	Dec. 30, 2016	Sep. 30, 2017	Sep. 30, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Purchase price of acquisition, cash					$ 21,235,000
Payment of contingent consideration					3,750,000
Goodwill	$ 31,343,000			$ 31,343,000	$ 31,343,000	$ 9,676,000
IDV Solutions LLC
Business Acquisition [Line Items]
Date of acquisition of business					Jan. 27, 2017
Purchase price of acquisition, cash		$ 21,200,000
Escrow deposit		2,500,000
Acquisition, preliminary purchase price		5,000,000			$ 26,255,000
Payment of contingent consideration	3,800,000
Weighted average useful life of identified acquired intangible assets					4 years 3 months 4 days
Goodwill	$ 21,196,000	$ 21,200,000		21,196,000	$ 21,196,000
Business acquisition transaction costs				$ 0	$ 100,000
IDV Solutions LLC | Developed Technology
Business Acquisition [Line Items]
Weighted average useful life of identified acquired intangible assets					3 years
IDV Solutions LLC | Customer Relationships
Business Acquisition [Line Items]
Weighted average useful life of identified acquired intangible assets					5 years
IDV Solutions LLC | Non-compete Arrangement
Business Acquisition [Line Items]
Weighted average useful life of identified acquired intangible assets					2 years
IDV Solutions LLC | Trade Names
Business Acquisition [Line Items]
Weighted average useful life of identified acquired intangible assets					5 years
IDV Solutions LLC | Minimum
Business Acquisition [Line Items]
Business acquisition, billings threshold date					Jun. 30, 2017
Weighted average life (years)					2 years
IDV Solutions LLC | Maximum
Business Acquisition [Line Items]
Business acquisition, billings threshold date					Dec. 31, 2017
Weighted average life (years)					5 years
Crisis Commander
Business Acquisition [Line Items]
Acquisition, preliminary purchase price			$ 2,700,000
Business acquisition closing date					Dec. 30, 2016