Summarizes Cost And Estimated Fair Value Of Short Term Fixed Income Securities (Detail) - USD ($) $ in Thousands	Dec. 30, 2016	Jan. 01, 2016
Fair Value Measurements [Line Items]
Due within one year, Amortized Cost	$ 16,000
Due between one and two years, Amortized Cost	43,000
Total Amortized Cost	59,000
Due within one year, Estimated Fair Value	15,992
Due between one and two years, Estimated Fair Value	42,763
Total Estimated Fair Value	$ 58,755	$ 45,842