Goodwill and Identified Intangible Assets - Summary of Goodwill and Identified Intangible Assets (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 26, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 85,495	$ 85,478
Accumulated Amortization	(83,502)	(81,017)
Total future amortization expense	1,993	4,461
Developed Core Technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	31,707	31,707
Accumulated Amortization	(31,707)	(30,757)
Total future amortization expense	$ 0	950
Customer relationships/contracts
Finite-Lived Intangible Assets [Line Items]
Useful Life	8 months 12 days
Gross Carrying Amount	$ 44,588	44,577
Accumulated Amortization	(42,595)	(41,092)
Total future amortization expense	1,993	3,485
Trademarks and Trade Names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	611	609
Accumulated Amortization	(611)	(583)
Total future amortization expense	0	26
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	3,089	3,085
Accumulated Amortization	(3,089)	(3,085)
Total future amortization expense	$ 0	$ 0