Cash, Cash Equivalents And Short Term Investments (Detail) - USD ($) $ in Thousands	Oct. 02, 2015	Jan. 02, 2015
Fair Value Measurements [Line Items]
Amortized Cost	$ 151,278	$ 154,380
Unrealized Gains	17	27
Unrealized Losses	(1)	(4)
Estimated Fair Value	151,294	154,403
U.S. Agency Securities
Fair Value Measurements [Line Items]
Amortized Cost	16,000
Unrealized Gains	14
Unrealized Losses	0
Estimated Fair Value	16,014
Cash
Fair Value Measurements [Line Items]
Amortized Cost	120,849	84,012
Unrealized Gains	0	0
Unrealized Losses	0	0
Estimated Fair Value	120,849	84,012
Money market securities
Fair Value Measurements [Line Items]
Amortized Cost	3,608	45,478
Unrealized Gains	0	0
Unrealized Losses	0	0
Estimated Fair Value	3,608	45,478
Total cash equivalents
Fair Value Measurements [Line Items]
Amortized Cost	3,608	45,478
Unrealized Gains	0	0
Unrealized Losses	0	0
Estimated Fair Value	3,608	45,478
Total cash and cash equivalents
Fair Value Measurements [Line Items]
Amortized Cost	124,457	129,490
Unrealized Gains	0	0
Unrealized Losses	0	0
Estimated Fair Value	124,457	129,490
State and municipal bonds
Fair Value Measurements [Line Items]
Amortized Cost	10,821	24,890
Unrealized Gains	3	27
Unrealized Losses	(1)	(4)
Estimated Fair Value	10,823	24,913
Total short-term investments
Fair Value Measurements [Line Items]
Amortized Cost	26,821	24,890
Unrealized Gains	17	27
Unrealized Losses	(1)	(4)
Estimated Fair Value	$ 26,837	$ 24,913