Business Combinations - Additional Information (Details) - USD ($) $ in Thousands					12 Months Ended
	May 18, 2018	May 01, 2018	Apr. 03, 2018	Jan. 27, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Purchase price of acquisition, cash					$ 35,857	$ 21,235	$ 2,306
Goodwill					48,382	31,328	$ 9,676
Payment of contingent consideration					$ 431	3,750
Minimum
Business Acquisition [Line Items]
Estimated useful life					1 year
Maximum
Business Acquisition [Line Items]
Estimated useful life					7 years
Customer Relationships
Business Acquisition [Line Items]
Weighted average useful life of identified acquired intangible assets					5 years
Trade Names | Minimum
Business Acquisition [Line Items]
Weighted average useful life of identified acquired intangible assets					2 years
Trade Names | Maximum
Business Acquisition [Line Items]
Weighted average useful life of identified acquired intangible assets					8 years
UMS
Business Acquisition [Line Items]
Date of acquisition of business			Apr. 03, 2018
Purchase price of acquisition, cash			$ 31,900
Weighted average useful life of identified acquired intangible assets					6 years 7 months 17 days
Goodwill			$ 18,300		$ 18,278
Business acquisition transaction costs					400
Total purchase price					$ 31,884
UMS | Acquired Technology
Business Acquisition [Line Items]
Weighted average useful life of identified acquired intangible assets					3 years
UMS | Customer Relationships
Business Acquisition [Line Items]
Weighted average useful life of identified acquired intangible assets					7 years
UMS | Trade Names
Business Acquisition [Line Items]
Weighted average useful life of identified acquired intangible assets					1 year
PlanetRisk, Inc.
Business Acquisition [Line Items]
Date of acquisition of business		May 01, 2018
Purchase price of acquisition, cash		$ 2,000
Weighted average useful life of identified acquired intangible assets					6 years 9 months 27 days
Goodwill		$ 200			$ 228
Business acquisition transaction costs					100
Total purchase price					$ 2,021
PlanetRisk, Inc. | Acquired Technology
Business Acquisition [Line Items]
Weighted average useful life of identified acquired intangible assets					3 years
PlanetRisk, Inc. | Customer Relationships
Business Acquisition [Line Items]
Weighted average useful life of identified acquired intangible assets					7 years
Respond B.V.
Business Acquisition [Line Items]
Date of acquisition of business	May 18, 2018
Purchase price of acquisition, cash	$ 2,000
Weighted average useful life of identified acquired intangible assets					6 years 4 months 24 days
Goodwill	1,200				$ 1,193
Business acquisition transaction costs					100
Note payable	400				383
Total purchase price	$ 2,300				$ 2,335
Respond B.V. | Acquired Technology
Business Acquisition [Line Items]
Weighted average useful life of identified acquired intangible assets					3 years
Respond B.V. | Customer Relationships
Business Acquisition [Line Items]
Weighted average useful life of identified acquired intangible assets					7 years
Respond B.V. | Trade Names
Business Acquisition [Line Items]
Weighted average useful life of identified acquired intangible assets					1 year
IDV Solutions LLC
Business Acquisition [Line Items]
Date of acquisition of business				Jan. 27, 2017
Purchase price of acquisition, cash				$ 21,200
Weighted average useful life of identified acquired intangible assets					4 years 3 months 3 days
Goodwill				21,200		21,196
Business acquisition transaction costs						100
Note payable						5,020
Total purchase price						$ 26,255
Escrow deposit				$ 2,500
Escrow deposit period				15 months
Recognition of obligation				$ 5,000
Payment of contingent consideration					$ 3,800
IDV Solutions LLC | Minimum
Business Acquisition [Line Items]
Business acquisition, billings threshold date				Jun. 30, 2017
Estimated useful life					2 years
IDV Solutions LLC | Maximum
Business Acquisition [Line Items]
Business acquisition, billings threshold date				Dec. 31, 2017
Estimated useful life					5 years
IDV Solutions LLC | Acquired 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 | Trade Names
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