Cash, Cash Equivalents And Short Term Investments (Detail) - USD ($) $ in Thousands	Jul. 03, 2015	Jan. 02, 2015
Fair Value Measurements [Line Items]
Amortized Cost	$ 149,867	$ 154,380
Unrealized Gains	3	27
Unrealized Losses	(8)	(4)
Estimated Fair Value	149,862	154,403
U.S. Agency Securities
Fair Value Measurements [Line Items]
Amortized Cost	4,000
Unrealized Gains	0
Unrealized Losses	(2)
Estimated Fair Value	3,998
Cash
Fair Value Measurements [Line Items]
Amortized Cost	123,418	84,012
Unrealized Gains	0	0
Unrealized Losses	0	0
Estimated Fair Value	123,418	84,012
Money market securities
Fair Value Measurements [Line Items]
Amortized Cost	8,509	45,478
Unrealized Gains	0	0
Unrealized Losses	0	0
Estimated Fair Value	8,509	45,478
Total cash equivalents
Fair Value Measurements [Line Items]
Amortized Cost	8,509	45,478
Unrealized Gains	0	0
Unrealized Losses	0	0
Estimated Fair Value	8,509	45,478
Total cash and cash equivalents
Fair Value Measurements [Line Items]
Amortized Cost	131,927	129,490
Unrealized Gains	0	0
Unrealized Losses	0	0
Estimated Fair Value	131,927	129,490
State and municipal bonds
Fair Value Measurements [Line Items]
Amortized Cost	13,940	24,890
Unrealized Gains	3	27
Unrealized Losses	(6)	(4)
Estimated Fair Value	13,937	24,913
Total short-term investments
Fair Value Measurements [Line Items]
Amortized Cost	17,940	24,890
Unrealized Gains	3	27
Unrealized Losses	(8)	(4)
Estimated Fair Value	$ 17,935	$ 24,913