Summary of Acquired Intangible Assets (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 27, 2015	Dec. 28, 2014
Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets, Gross Carrying Amount	$ 365.7	$ 367.0
Total identifiable intangible assets, Accumulated Amortization	(335.7)	(329.8)
Developed Technology
Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets, Gross Carrying Amount	260.4	261.4
Total identifiable intangible assets, Accumulated Amortization	$ (247.5)	(245.3)
Developed Technology | Minimum
Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets, Period of Amortization	8 years
Developed Technology | Maximum
Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets, Period of Amortization	10 years
Customer Base
Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets, Gross Carrying Amount	$ 85.8	86.1
Total identifiable intangible assets, Accumulated Amortization	$ (80.1)	(77.4)
Customer Base | Minimum
Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets, Period of Amortization	6 years
Customer Base | Maximum
Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets, Period of Amortization	10 years
Core Technology
Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets, Gross Carrying Amount	$ 15.7	15.7
Total identifiable intangible assets, Accumulated Amortization	$ (7.0)	(6.3)
Core Technology | Minimum
Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets, Period of Amortization	10 years
Core Technology | Maximum
Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets, Period of Amortization	15 years
In Process R&D
Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets, Gross Carrying Amount	$ 3.3	3.3
Total identifiable intangible assets, Accumulated Amortization	$ (0.9)	(0.7)
In Process R&D | Minimum
Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets, Period of Amortization	3 years
In Process R&D | Maximum
Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets, Period of Amortization	10 years
Trademarks and trade names
Finite-Lived Intangible Assets [Line Items]
Total identifiable intangible assets, Period of Amortization	5 years
Total identifiable intangible assets, Gross Carrying Amount	$ 0.5	0.5
Total identifiable intangible assets, Accumulated Amortization	$ (0.2)	$ (0.1)