Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash flows from operating activities:
Net earnings	$ 357,929	$ 265,356	$ 184,357
Adjustments to reconcile net earnings to net cash provided by operating activities, net of acquisitions:
Depreciation of property and equipment	44,113	40,688	40,020
Loss on sale of property and equipment	194	35	850
Bad debt expense	9,217	8,658	9,409
Deferred income taxes	15,747	1,602	6,099
Stock based compensation	4,050	4,030	3,850
Amortization of non-compete agreement	593	67	67
Changes in operating assets and liabilities, net of impact of acquisition:
Trade accounts receivable	(77,678)	(64,622)	21,362
Inventories	(88,783)	(48,964)	60,425
Other current assets	(19,294)	(24,577)	17,747
Accounts payable	13,305	6,984	(14,172)
Accrued expenses	15,550	30,393	(17,526)
Income taxes	(3,222)	16,956	(12,156)
Other	(3,232)	3,882	5,738
Net cash provided by operating activities	268,489	240,488	306,070
Cash flows from investing activities:
Purchase of property and equipment	(120,043)	(73,597)	(52,538)
Cash paid for acquisition	0	0	(5,032)
Proceeds from sale of property and equipment	3,554	4,459	4,863
Net decrease (increase) in marketable securities	4,054	(581)	(28,941)
Decrease (increase) in other assets	212	(10,329)	(101)
Net cash used in investing activities	(112,223)	(80,048)	(81,749)
Cash flows from financing activities:
Proceeds from exercise of stock options	8,939	0	0
Tax benefits from exercise of stock options	983	0	0
Purchase of common stock	0	0	(41,104)
Payment of dividends	(191,741)	(182,814)	(106,943)
Net cash used in financing activities	(181,819)	(182,814)	(148,047)
Effect of exchange rate changes on cash	(464)	1,215	2,686
Net (decrease) increase in cash and cash equivalents	(26,017)	(21,159)	78,960
Cash and cash equivalents at beginning of year	143,693	164,852	85,892
Cash and cash equivalents at end of year	117,676	143,693	164,852
Supplemental disclosure of cash flow information:
Cash paid during each year for income taxes	$ 205,614	$ 146,726	$ 118,035