Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Operating activities
Net income	$ 3,440	$ 3,651
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation	3,073	2,664
Amortization	321	320
Share-based compensation	1,905	2,101
Excess tax benefits from share-based compensation	(1,703)	(1,138)
Equity earnings in unconsolidated investments	(18)	(144)
Other	(38)	941
Changes in operating assets and liabilities, net of effects of acquisitions:
Receivables	(74,283)	(90,350)
Product inventories	(94,786)	(72,788)
Prepaid expenses and other assets	(2,461)	(1,395)
Accounts payable	137,896	140,530
Accrued expenses and other current liabilities	(13,332)	(18,419)
Net cash used in operating activities	(39,986)	(34,027)
Investing activities
Acquisition of businesses, net of cash acquired	(325)	(3,855)
Purchase of property and equipment, net of sale proceeds	(4,882)	(6,661)
Other investments, net	9	(53)
Net cash used in investing activities	(5,198)	(10,569)
Financing activities
Proceeds from revolving line of credit	149,760	215,411
Payments on revolving line of credit	(102,100)	(63,700)
Payments on long-term debt and other long-term liabilities	(5)	(100,005)
Excess tax benefits from share-based compensation	1,703	1,138
Proceeds from stock issued under share-based compensation plans	6,438	4,178
Payments of cash dividends	(7,434)	(6,668)
Purchases of treasury stock	(3,829)	(2,369)
Net cash provided by financing activities	44,533	47,985
Effect of exchange rate changes on cash and cash equivalents	1,061	(195)
Change in cash and cash equivalents	410	3,194
Cash and cash equivalents at beginning of period	12,463	17,487
Cash and cash equivalents at end of period	$ 12,873	$ 20,681