Subsequent Events - Additional Information (Detail) - USD ($) $ in Thousands		3 Months Ended
	Apr. 11, 2016	Mar. 31, 2016	Mar. 31, 2015
Subsequent Event [Line Items]
Direct and incremental expenses		$ 919	$ 26
OpenSpan
Subsequent Event [Line Items]
Direct and incremental expenses		$ 919
Subsequent Event | OpenSpan
Subsequent Event [Line Items]
Purchase price of acquired company	$ 52,300
Escrow deposit	$ 7,600
Deposited in escrow period	18 months
Amount of purchase price subject to holdback and contingent on achievement of revenue targets	$ 1,500
Contingent consideration, measurement date for achievement of revenue targets	Jun. 30, 2016