Short-Term Investments - Maturities of Short-Term Investments (Detail) - USD ($) $ in Thousands	Oct. 02, 2015	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Less than one year	$ 20,545	$ 30,946
Due in 1 - 2 years	5,445	901
Total short-term investments, Estimated Fair Value	$ 25,990	$ 31,847