Stock Compensation Plan - Restricted Stock Unit Activity (Parenthetical) (Detail)	0 Months Ended									12 Months Ended
	Jul. 02, 2012	Jan. 02, 2012	Jan. 10, 2012	Jul. 02, 2011	Jan. 02, 2011	Jan. 10, 2011	Jul. 02, 2010	Jan. 02, 2010	Jan. 10, 2010	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Treasury stock authorized to satisfy minimum statutory tax withholding requirements	3,953	594	79,035	4,121	52,138	82,174	4,121	55,159	87,881	83,582	138,433	147,161
Class A Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Treasury stock authorized to satisfy minimum statutory tax withholding requirements
Treasury Stock [Member] | Class A Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Treasury stock authorized to satisfy minimum statutory tax withholding requirements										83,582	138,433	147,161