Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 26, 2015	Sep. 27, 2014	Sep. 26, 2015	Sep. 27, 2014
Consolidated Statements of Income [Abstract]
Net sales	$ 711,879	$ 683,893	$ 2,142,685	$ 2,062,894
Cost of sales, including warehousing and distribution expenses	517,732	498,216	1,554,504	1,502,776
Gross profit on sales	194,147	185,677	588,181	560,118
Operating, general and administrative expenses	174,566	166,067	523,170	499,435
Income from operations	19,581	19,610	65,011	60,683
Investment income (loss)	(422)	357	695	1,766
Income before provision for income taxes	19,159	19,967	65,706	62,449
Provision for income taxes	6,371	6,456	22,952	21,767
Net income	$ 12,788	$ 13,511	$ 42,754	$ 40,682
Weighted-average shares outstanding, basic and diluted	26,898,443	26,898,443	26,898,443	26,898,443
Cash dividends per share	$ 0.30	$ 0.30	$ 0.90	$ 0.90
Basic and diluted earnings per share	$ 0.48	$ 0.50	$ 1.59	$ 1.51