Stock Based Compensation - Additional Information (Detail) (USD $)	12 Months Ended								12 Months Ended
	Dec. 28, 2012	Dec. 30, 2011	Dec. 31, 2010	Dec. 28, 2012 Employee Stock Purchase Plan	Dec. 30, 2011 Employee Stock Purchase Plan	Dec. 31, 2010 Employee Stock Purchase Plan	Dec. 28, 2012 2008 Equity Incentive Plan	May 29, 2008 2008 Equity Incentive Plan	Dec. 28, 2012 Stock Options Granted Prior To Decemeber 2005	Dec. 30, 2011 Stock Options Granted Prior To Decemeber 2005	Dec. 31, 2010 Stock Options Granted Prior To Decemeber 2005	Dec. 28, 2012 Stock Options Granted After Decemeber 2005	Dec. 30, 2011 Stock Options Granted After Decemeber 2005	Dec. 31, 2010 Stock Options Granted After Decemeber 2005	Dec. 28, 2012 Vested Restricted Stock	Dec. 30, 2011 Vested Restricted Stock	Dec. 31, 2010 Vested Restricted Stock	Dec. 28, 2012 Unvested Restricted Stock	Dec. 30, 2011 Unvested Restricted Stock	Dec. 31, 2010 Unvested Restricted Stock	Dec. 28, 2012 Unvested Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total number of shares reserved for issuance				200,000				2,414,075
Number of shares available for grant				81,796			1,189,291
Maximum payroll deduction for purchase of common stock				15.00%
Purchase price of common stock as a percentage of fair market value				95.00%
Weighted average purchase price				$ 50.26	$ 41.70	$ 30.72
Stock based compensation expense									$ 37,000	$ 34,000	$ 31,000	$ 602,000	$ 547,000	$ 616,000	$ 6,089,000	$ 5,295,000	$ 4,533,000	$ 5,650,000	$ 4,464,000	$ 4,077,000
Total intrinsic value of options exercised	7,484,000	2,995,000	8,086,000
Weighted average fair value of options granted	$ 19.51	$ 16.51	$ 11.70
Unrecognized compensation cost																		$ 5,191,000			$ 678,000
Weighted average period of recognized term																		2 years 4 months 24 days			2 years 2 months 12 days
Percentage of annual bonus settled with fully vested restricted stock unit awards															40.00%
Recipient age to expense award on grant date															59 years 6 months