Goodwill and Identified Intangible Assets - Summary of Goodwill and Identified Intangible Assets (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 87,487	$ 45,687
Accumulated Amortization	(54,366)	(41,590)
Total future amortization expense	$ 33,121	4,097
Developed Technology
Finite-Lived Intangible Assets [Line Items]
Useful Life	3 years 4 months 12 days
Gross Carrying Amount	$ 33,057	10,987
Accumulated Amortization	(14,112)	(10,987)
Total future amortization expense	$ 18,945	0
Customer relationships/contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Useful Life	4 years 4 months 24 days
Gross Carrying Amount	$ 44,659	29,200
Accumulated Amortization	(31,004)	(25,752)
Total future amortization expense	$ 13,655	3,448
Trademarks and Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Useful Life	3 years 4 months 12 days
Gross Carrying Amount	$ 610
Accumulated Amortization	(89)
Total future amortization expense	521
Maintenance agreements and related relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	5,500	5,500
Accumulated Amortization	(5,500)	(4,851)
Total future amortization expense	0	$ 649
Backlog
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,661
Accumulated Amortization	(3,661)
Total future amortization expense	$ 0