Consolidated Statements of Income (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
Mar. 28, 2015	Mar. 29, 2014
Consolidated Statements of Income [Abstract]
Net sales	$ 712,426us-gaap_SalesRevenueGoodsNet	$ 687,127us-gaap_SalesRevenueGoodsNet
Cost of sales, including warehousing and distribution expenses	517,311	500,359
Gross profit on sales	195,115us-gaap_GrossProfit	186,768us-gaap_GrossProfit
Operating, general and administrative expenses	175,614us-gaap_GeneralAndAdministrativeExpense	164,465us-gaap_GeneralAndAdministrativeExpense
Income from operations	19,501us-gaap_OperatingIncomeLoss	22,303us-gaap_OperatingIncomeLoss
Investment income	532us-gaap_InvestmentIncomeNet	753us-gaap_InvestmentIncomeNet
Income before provision for income taxes	20,033	23,056
Provision for income taxes	6,924us-gaap_IncomeTaxExpenseBenefit	8,290us-gaap_IncomeTaxExpenseBenefit
Net income	$ 13,109us-gaap_NetIncomeLoss	$ 14,766us-gaap_NetIncomeLoss
Weighted-average shares outstanding, basic and diluted	26,898,443	26,898,443
Cash dividends per share	$ 0.30	$ 0.30
Basic and diluted earnings per share	$ 0.49us-gaap_EarningsPerShareBasicAndDiluted	$ 0.55us-gaap_EarningsPerShareBasicAndDiluted

Aggregate dividends declared during the period for each share of common stock outstanding.

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