CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Operating activities
Net income	$ 18,427	$ 17,577
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	11,803	11,908
Provision for doubtful accounts	89	25
Deferred income taxes	482	1,059
Excess tax benefits from stock based compensation	(372)	(67)
(Gain) loss on disposal or impairment of assets	(8)	(2)
Foreign currency transaction loss, net	23	12
Stock compensation expense	2,086	1,757
Changes in operating assets and liabilities:
Trade accounts and other receivables	17,701	(5,767)
Inventories	(7,352)	(6,893)
Prepaid expenses and other current assets	680	(542)
Long-term prepaid expenses	(1,927)	855
Accounts payable	134	(1,276)
Accrued expenses	(6,235)	(7,727)
Accrued income taxes, net	8,578	6,108
Net cash provided by operating activities	44,109	17,027
Investing activities
Capital expenditures	(38,908)	(13,752)
Net cash used in investing activities	(38,908)	(13,752)
Financing activities
Dividends paid	(6,945)	(6,256)
Purchase of common stock	(5,779)	(3,671)
Excess tax benefits from stock based compensation	372	67
Net cash used in financing activities	(12,352)	(9,860)
Effect of exchange rate changes on cash	(1,001)	(253)
Net decrease in cash and cash equivalents	(8,152)	(6,838)
Cash and cash equivalents at beginning of period	94,250	90,635
Cash and cash equivalents at end of period	86,098	83,797
Supplemental cash flow information
Interest paid	10	1
Income taxes paid	$ 16	$ 761