Summary of Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 26, 2015	Sep. 26, 2015	Jun. 27, 2015	Mar. 28, 2015	Dec. 27, 2014	Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Dec. 26, 2015	Dec. 27, 2014	Dec. 28, 2013
Summary of Quarterly Results [Abstract]
Net sales	$ 734,063	$ 711,879	$ 718,380	$ 712,426	$ 713,788	$ 683,893	$ 691,875	$ 687,127	$ 2,876,748	$ 2,776,683	$ 2,692,588
Gross profit on sales	198,551	194,147	198,919	195,115	192,793	185,677	187,724	186,768	786,732	752,962	745,468
Net income	$ 16,575	$ 12,788	$ 16,644	$ 13,323	$ 13,698	$ 13,511	$ 12,602	$ 14,570	$ 59,330	$ 54,381	$ 73,186
Basic and diluted earnings per share	$ 0.61	$ 0.48	$ 0.62	$ 0.50	$ 0.51	$ 0.50	$ 0.47	$ 0.54	$ 2.21	$ 2.02	$ 2.72