Balance Sheet Components - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended	9 Months Ended
	Sep. 28, 2013	Sep. 28, 2013	Sep. 30, 2012
Other Assets [Line Items]
Other offering expenses		$ 0.1
IPO
Other Assets [Line Items]
Other offering expenses	$ 4.0	$ 4.0	$ 4.0