Acquisitions - Additional Information (Detail) $ in Thousands			12 Months Ended
	Jul. 19, 2016 USD ($) Employee	Apr. 07, 2016 USD ($)	Dec. 31, 2017	Dec. 31, 2016 USD ($)
Business Acquisition [Line Items]
Total purchase price				$ 4,318
Total cash consideration				2,485
Birdstep Technology AB [Member]
Business Acquisition [Line Items]
Acquisition agreement date			Mar. 08, 2016
Business acquisition, equity interests acquired		100.00%
Total purchase price		$ 2,000
Birdstep Technology AB [Member] | General and Administrative [Member]
Business Acquisition [Line Items]
Acquisition-related costs				200
iMobileMagic - Mobile Experiences LDA [Member]
Business Acquisition [Line Items]
Acquisition agreement date			Jul. 19, 2016
Business acquisition, equity interests acquired	100.00%
Acquisition-related costs				$ 200
Purchase price in cash	$ 2,300
Total cash consideration	600
Buyers common stock initial shares	600
Buyers common stock in escrow	$ 1,100
Number of employees | Employee	16