Condensed Consolidated Statements Of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Net sales	$ 361,457us-gaap_SalesRevenueGoodsNet	$ 285,377us-gaap_SalesRevenueGoodsNet
Cost of sales	285,054us-gaap_CostOfGoodsSold	222,177us-gaap_CostOfGoodsSold
Gross profit	76,403us-gaap_GrossProfit	63,200us-gaap_GrossProfit
Selling, general and administrative expenses	44,565	37,154
Operating profit	31,838us-gaap_OperatingIncomeLoss	26,046us-gaap_OperatingIncomeLoss
Interest expense, net	189us-gaap_InterestIncomeExpenseNet	120us-gaap_InterestIncomeExpenseNet
Income before income taxes	31,649	25,926
Provision for income taxes	11,576us-gaap_IncomeTaxExpenseBenefit	9,762us-gaap_IncomeTaxExpenseBenefit
Net income	$ 20,073us-gaap_NetIncomeLoss	$ 16,164us-gaap_NetIncomeLoss
Net income per common share:
Basic (in usd per share)	$ 0.83us-gaap_EarningsPerShareBasic	$ 0.68us-gaap_EarningsPerShareBasic
Diluted (in usd per share)	$ 0.82us-gaap_EarningsPerShareDiluted	$ 0.67us-gaap_EarningsPerShareDiluted
Weighted average common shares outstanding:
Basic (in shares)	24,215	23,774
Diluted (in shares)	24,541	24,188

Total costs related to goods produced and sold during the reporting period.

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