Earning Per Share (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended						4 Months Ended		12 Months Ended
	Sep. 09, 2012	Jun. 17, 2012	Mar. 25, 2012	Sep. 11, 2011	Jun. 19, 2011	Mar. 27, 2011	Dec. 30, 2012	Jan. 01, 2012	Dec. 30, 2012	Jan. 01, 2012	Jan. 02, 2011
Earnings Per Share [Line Items]
Net income available to common stockholders - basic and diluted	$ 25,976	$ 28,095	$ 20,742	$ 22,091	$ 25,248	$ 27,111	$ 37,579	$ 30,911	$ 112,392	$ 105,361	$ 87,917
Weighted average number of common shares									56,419,645	58,918,038	58,467,769
Earnings per common share - basic	$ 0.46	$ 0.50	$ 0.36	$ 0.37	$ 0.42	$ 0.46	$ 0.67	$ 0.54	$ 1.99	$ 1.79	$ 1.50
Diluted weighted average number of common shares									58,997,476	61,653,519	60,815,898
Earnings per common share - diluted	$ 0.44	$ 0.47	$ 0.35	$ 0.36	$ 0.40	$ 0.43	$ 0.64	$ 0.52	$ 1.91	$ 1.71	$ 1.45