Goodwill and Identified Intangible Assets - Summary of Goodwill and Identified Intangible Assets (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 29, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 85,487	$ 85,592
Accumulated Amortization	(74,783)	(72,775)
Total future amortization expense	$ 10,704	12,817
Developed Core Technology
Finite-Lived Intangible Assets [Line Items]
Useful Life	10 months 24 days
Gross Carrying Amount	$ 31,707	31,707
Accumulated Amortization	(26,871)	(25,576)
Total future amortization expense	$ 4,836	6,131
Customer relationships/contracts
Finite-Lived Intangible Assets [Line Items]
Useful Life	1 year 10 months 24 days
Gross Carrying Amount	$ 44,583	44,650
Accumulated Amortization	(38,855)	(38,146)
Total future amortization expense	$ 5,728	6,504
Trademarks and Trade Names
Finite-Lived Intangible Assets [Line Items]
Useful Life	10 months 24 days
Gross Carrying Amount	$ 610	623
Accumulated Amortization	(470)	(441)
Total future amortization expense	140	182
Maintenance Agreements and Related Relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	5,500	5,500
Accumulated Amortization	(5,500)	(5,500)
Total future amortization expense	0	0
Order Backlog
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,087	3,112
Accumulated Amortization	(3,087)	(3,112)
Total future amortization expense	$ 0	$ 0