Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Cash flows from operating activities
Net income	$ 12,087	$ 4,795
Adjustments to reconcile net income to net cash used in operating activities:
Gain on sale of assets	(285)	(8)
Depreciation and amortization	7,684	7,487
Impairment loss on assets		1,024
Deferred income taxes	1,651	2,093
Noncash compensation related to stock plans	2,657	2,977
Excess tax benefit of options exercised	(8)
Provision for doubtful accounts	(53)	(39)
Changes in operating assets and liabilities, net of acquisitions:
Trade accounts receivable	(24,220)	(21,006)
Inventories	(19,128)	823
Trade accounts payable	(3,403)	(5,578)
Income taxes payable	4,140	927
Accrued profit sharing trust contributions	(3,770)	(3,335)
Accrued cash profit sharing and commissions	2,057	1,318
Other current assets	(2,977)	16
Accrued liabilities	(5,022)	(9,179)
Long-term liabilities	(950)	(612)
Accrued workers' compensation	528	(18)
Other noncurrent assets	54	(417)
Net cash used in operating activities	(28,958)	(18,732)
Cash flows from investing activities
Capital expenditures	(4,193)	(4,632)
Asset acquisitions, net of cash acquired		(5,300)
Proceeds from sale of property and equipment	451	17
Loan repayment by related parties		605
Net cash used in investing activities	(3,742)	(9,310)
Cash flows from financing activities
Deferred and contingent consideration paid for asset acquisition	(1,294)
Debt and line of credit borrowings		1,080
Repayment of debt and line of credit borrowings	(20)	(20)
Issuance of common stock	1,769	496
Excess tax benefit of options exercised	8
Dividends paid	(6,089)	(6,053)
Net cash used in financing activities	(5,626)	(4,497)
Effect of exchange rate changes on cash and cash equivalents	(894)	(1,049)
Net decrease in cash and cash equivalents	(39,220)	(33,588)
Cash and cash equivalents at beginning of period	251,208	175,553
Cash and cash equivalents at end of period	211,988	141,965
Noncash activity during the period
Noncash capital expenditures	406	140
Dividends declared but not paid	6,116
Issuance of Company's common stock for compensation	$ 402	$ 315