Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Consolidated Statements of Income [Abstract]
Net sales	$ 871,100	$ 876,569	$ 1,747,206	$ 1,728,798
Cost of sales, including advertising, warehousing and distribution expenses	630,805	642,811	1,272,004	1,266,004
Gross profit on sales	240,295	233,758	475,202	462,794
Operating, general and administrative expenses	214,258	206,040	426,326	414,826
Income from operations	26,037	27,718	48,876	47,968
Investment income and interest expense	105	412	(427)	1,236
Income before provision for income taxes	26,142	28,130	48,449	49,204
Provision for income taxes	7,047	9,655	13,163	18,893
Net income	$ 19,095	$ 18,475	$ 35,286	$ 30,311
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	$ 0.60	$ 0.60
Basic and diluted earnings per share	$ 0.71	$ 0.69	$ 1.31	$ 1.13