Goodwill and other intangible assets, net - additional information (Detail) (USD $)	3 Months Ended		9 Months Ended			3 Months Ended
	Sep. 28, 2014	Sep. 29, 2013	Sep. 28, 2014	Sep. 29, 2013	Sep. 28, 2014 Semprus Technology	Mar. 31, 2013 Axiom In Process Research and Development
Finite-Lived Intangible Assets [Line Items]
In-process research and development impairment	$ 0	$ 3,354,000	$ 0	$ 7,848,000		$ 4,500,000
Net assets					41,000,000
Amortization expense of intangible assets	$ 15,000,000	$ 12,500,000	$ 47,053,000	$ 37,072,000