Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating activities
Net income	$ 31,339	$ 22,270
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation	6,299	5,557
Amortization	470	365
Share-based compensation	3,321	3,003
Equity earnings in unconsolidated investments, net	(46)	(38)
Other	681	1,847
Changes in operating assets and liabilities, net of effects of acquisitions:
Receivables	(117,377)	(123,515)
Product inventories	(168,518)	(161,668)
Prepaid expenses and other assets	(3,843)	(2,617)
Accounts payable	222,285	234,581
Accrued expenses and other current liabilities	(18,760)	(12,209)
Net cash used in operating activities	(44,149)	(32,424)
Investing activities
Acquisition of businesses, net of cash acquired	(578)	0
Purchase of property and equipment, net of sale proceeds	(14,639)	(19,121)
Other investments, net	0	2
Net cash used in investing activities	(15,217)	(19,119)
Financing activities
Proceeds from revolving line of credit	148,335	213,189
Payments on revolving line of credit	(170,012)	(206,319)
Proceeds from asset-backed financing	80,000	55,000
Payments on asset-backed financing	(20,000)	(18,500)
Proceeds from short-term borrowings and current portion of long-term debt	10,798	11,441
Payments on short-term borrowings and current portion of long-term debt	(848)	(2,771)
Payments of deferred and contingent acquisition consideration	(265)	(199)
Payments of deferred financing costs	(8)	0
Proceeds from stock issued under share-based compensation plans	7,808	6,149
Payments of cash dividends	(15,011)	(12,799)
Purchases of treasury stock	(2,592)	(2,725)
Net cash provided by financing activities	38,205	42,466
Effect of exchange rate changes on cash and cash equivalents	24	530
Change in cash and cash equivalents	(21,137)	(8,547)
Cash and cash equivalents at beginning of period	29,940	21,956
Cash and cash equivalents at end of period	$ 8,803	$ 13,409