Summary of Significant Accounting Policies - Schedule of Reported Share-Based Compensation in Condensed Consolidated Interim Financial Statements (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 28, 2015	Mar. 29, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total share-based compensation	$ 1,729	$ 1,481
Income tax benefit	(44)	(41)
Total share-based compensation, net	1,685	1,440
Cost of Sales [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total share-based compensation	115	75
Research and Development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total share-based compensation	338	490
Selling, General and Administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total share-based compensation	$ 1,276	$ 916