Schedule of Amortizable Intangible Assets (Detail) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Oct. 02, 2016		Dec. 31, 2015
Finite-Lived Intangible Assets
Gross Carrying Amount	$ 497,547	[1]	$ 546,388	[2]
Accumulated Amortization	382,428	[1],[3]	303,227	[2]
Foreign Currency Translation Adjustment	(973)		(3,330)
Net Carrying Amount	$ 114,146		$ 239,831
Weighted Average Useful Life, years	6 years 9 months 18 days		6 years 8 months 12 days
Developed technology
Finite-Lived Intangible Assets
Gross Carrying Amount	$ 333,421	[1]	$ 382,262	[2]
Accumulated Amortization	264,248	[1],[3]	220,346	[2]
Foreign Currency Translation Adjustment	(714)		(2,444)
Net Carrying Amount	$ 68,459		$ 159,472
Weighted Average Useful Life, years	6 years		6 years
Customer Relationships
Finite-Lived Intangible Assets
Gross Carrying Amount	$ 110,602	[1]	$ 110,602	[2]
Accumulated Amortization	92,139	[1],[3]	63,722	[2]
Foreign Currency Translation Adjustment	(75)		(258)
Net Carrying Amount	$ 18,388		$ 46,622
Weighted Average Useful Life, years	7 years 10 months 24 days		7 years 10 months 24 days
Trademarks and tradenames
Finite-Lived Intangible Assets
Gross Carrying Amount	$ 53,034	[1]	$ 53,034	[2]
Accumulated Amortization	25,711	[1],[3]	18,889	[2]
Foreign Currency Translation Adjustment	(184)		(628)
Net Carrying Amount	$ 27,139		$ 33,517
Weighted Average Useful Life, years	9 years 6 months		9 years 6 months
Non-compete agreements
Finite-Lived Intangible Assets
Gross Carrying Amount	$ 320	[1]	$ 320	[2]
Accumulated Amortization	160	[1],[3]	100	[2]
Net Carrying Amount	$ 160		$ 220
Weighted Average Useful Life, years	4 years		4 years
Customer backlog
Finite-Lived Intangible Assets
Gross Carrying Amount	$ 170	[1]	$ 170	[2]
Accumulated Amortization	$ 170	[1],[3]	$ 170	[2]
Weighted Average Useful Life, years	3 months 18 days		3 months 18 days

[1] In 2016, $48 million of amortizable intangible assets became fully amortized and have been eliminated from the gross carrying amount and accumulated amortization.

[2] In 2015, $98.2 million of amortizable intangible assets became fully amortized and have been eliminated from the gross carrying amount and accumulated amortization.

[3] Includes an $83 million impairment of Wireless Test amortizable intangible assets.