Option Activity (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 28, 2012		Dec. 30, 2011		Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares outstanding, Options Balance	435,396	[1]	511,140	[1]	817,109	[1]
Number of shares outstanding, Options Granted	25,000	[1]	30,000	[1]	42,500	[1]
Number of shares outstanding, Options Cancelled	(2,000)	[1]	0	[1]	0	[1]
Number of shares outstanding, Options Exercised	(200,268)	[1]	(105,744)	[1]	(348,469)	[1]
Number of shares outstanding, awards balance:	258,128	[1]	435,396	[1]	511,140	[1]
Number of shares outstanding, Vested and expected to vest	252,180	[1]
Number of shares outstanding, Exercisable	173,874	[1]
Weighted-average exercise price, Options Balance	$ 17.60	[1]	$ 15.69	[1]	$ 11.74	[1]
Weighted-average exercise price, Options Granted	$ 48.27	[1]	$ 37.72	[1]	$ 25.96	[1]
Weighted-average exercise price, Options Cancelled	$ 6.50	[1]	$ 0	[1]	$ 0	[1]
Weighted-average exercise price, Options Exercised	$ 13.01	[1]	$ 14.07	[1]	$ 7.67	[1]
Weighted-average exercise price, Options Balance	$ 24.21	[1]	$ 17.60	[1]	$ 15.69	[1]
Weighted-average exercise price, Options Vested and Expected to Vest	$ 24.08	[1]
Weighted-average exercise price, Exercisable	$ 19.39	[1]
Weighted average remaining contractual term, Balance	4 years 11 months 26 days	[1]
Weighted average remaining contractual term, Vested and Expected to Vest	4 years 11 months 12 days	[1]
Weighted average remaining contractual term, Exercisable	3 years 10 months 2 days	[1]
Aggregate intrinsic value, Balance	$ 7,611	[1]
Aggregate intrinsic value, Vested and Expected to Vest	7,471	[1]
Aggregate intrinsic value, Exercisable	$ 5,966	[1]

[1] Does not include restricted stock or employee stock purchase plans