Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Operating activities
Net Income (loss)	$ 164,027	$ 148,388
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation	13,558	12,888
Amortization	713	938
Share-based compensation	6,594	6,481
Equity earnings in unconsolidated investments, net	(134)	(106)
Other	2,558	1,861
Changes in operating assets and liabilities, net of effects of acquisitions:
Receivables	(206,271)	(210,327)
Product inventories	(5,380)	(76,286)
Prepaid expenses and other assets	4,831	2,100
Accounts payable	97,232	55,964
Accrued expenses and other current liabilities	19,713	21,290
Net cash provided by (used in) operating activities	97,441	(36,809)
Investing activities
Acquisition of businesses, net of cash acquired	(9,345)	(578)
Purchases of property and equipment, net of sale proceeds	(19,193)	(24,620)
Net cash used in investing activities	(28,538)	(25,198)
Financing activities
Proceeds from revolving line of credit	545,834	554,536
Payments on revolving line of credit	(657,180)	(545,574)
Proceeds from asset-backed financing	176,100	177,500
Payments on asset-backed financing	(54,200)	(60,000)
Proceeds from short-term borrowings and current portion of long-term debt	22,687	13,957
Payments on short-term borrowings and current portion of long-term debt	(7,881)	(3,330)
Payments of deferred and contingent acquisition consideration	(311)	(265)
Payments of deferred financing costs	0	(8)
Proceeds from stock issued under share-based compensation plans	12,603	9,383
Payments of cash dividends	(39,753)	(33,194)
Purchases of treasury stock	(23,097)	(38,876)
Net cash (used in) provided by financing activities	(25,198)	74,129
Effect of exchange rate changes on cash and cash equivalents	631	105
Change in cash and cash equivalents	44,336	12,227
Cash and cash equivalents at beginning of period	16,358	29,940
Cash and cash equivalents at end of period	$ 60,694	$ 42,167