Consolidated Statements of Cash Flows (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Operating activities
Net income	$ 82,108	$ 69,443
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	7,071	6,732
Amortization	1,243	1,827
Share-based compensation	6,143	5,912
Excess tax benefits from share-based compensation	(2,229)	(1,271)
Equity earnings in unconsolidated investments	(185)	(117)
Other	(3,892)	(7,673)
Changes in operating assets and liabilities, net of effects of acquisitions:
Receivables	(55,941)	(49,043)
Product inventories	10,999	55,482
Accounts payable	(49,542)	(55,586)
Other current assets and liabilities	36,199	39,536
Net cash provided by operating activities	31,974	65,242
Investing activities
Acquisition of businesses, net of cash acquired	(2,961)	(4,872)
Purchase of property and equipment, net of sale proceeds	(16,959)	(6,600)
Other investments	(177)	0
Net cash used in investing activities	(20,097)	(11,472)
Financing activities
Proceeds from revolving line of credit	446,649	370,639
Payments on revolving line of credit	(376,649)	(354,668)
Payments on long-term debt and other long-term liabilities	(145)	(36,160)
Payments of deferred acquisition consideration	(500)	(500)
Payments of deferred financing costs	0	(145)
Excess tax benefits from share-based compensation	2,229	1,271
Proceeds from stock issued under share-based compensation plans	9,506	4,717
Payments of cash dividends	(19,798)	(19,308)
Purchases of treasury stock	(62,842)	(1,534)
Net cash used in financing activities	(1,550)	(35,688)
Effect of exchange rate changes on cash and cash equivalents	608	(1,364)
Change in cash and cash equivalents	10,935	16,718
Cash and cash equivalents at beginning of period	9,721	15,843
Cash and cash equivalents at end of period	$ 20,656	$ 32,561