Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Jun. 09, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Acquired Finite Lived Intangible Assets [Line Items]
Measurement period adjustment				$ (549)
Weighted-average amortization period for intangible assets				10 years 6 months
Amortization of intangible assets		$ 3,317	$ 3,191	$ 9,825	$ 8,572
Customer Lists [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Weighted-average amortization period for intangible assets				11 years
Patents and Technology [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Weighted-average amortization period for intangible assets				9 years 3 months 18 days
Trade Names and Trademarks [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Weighted-average amortization period for intangible assets				1 year 2 months 12 days
Blue Tree Systems Limited [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Measurement period adjustment				$ 393
Inthinc [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Measurement period adjustment				$ 156
Inthinc [Member] | Customer Lists [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Weighted-average amortization period for intangible assets	15 years