Stock Repurchases (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Number of shares
Repurchased at beginning of period	11,538,680	10,921,933	10,892,459
Repurchases	944,876	616,747	29,474
Repurchased at end of period	12,483,556	11,538,680	10,921,933
Aggregate Purchase Price
Repurchased at beginning balance	$ 446,092	$ 307,387	$ 299,528
Repurchases	161,658	138,705	7,859
Repurchased at end of period	$ 607,750	$ 446,092	$ 307,387