CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities
Net income	$ 20,350	$ 15,359
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation expense	12,445	12,024
Amortization of intangible assets	4,347	3,657
Amortization of debt issuance costs	421	421
Deferred income taxes	6,771	3,810
Non-cash stock compensation expense	2,915	1,775
(Gain) loss on sale of property, equipment and real estate	(913)	38
Other non-cash adjustments	1,778	619
Change in assets and liabilities, net of effects of acquisitions
Accounts receivable, net of allowances	(9,463)	(33,462)
Inventories, net	1,499	(24,042)
Accounts payable	69,741	40,212
Other assets and liabilities	(32,132)	2,801
Net cash provided by operating activities	77,759	23,212
Cash flows from investing activities
Purchases of businesses, net of cash acquired	(52,012)	(20,970)
Purchases of property, equipment and real estate	(15,429)	(10,244)
Proceeds from sale of property, equipment and real estate	2,343	127
Insurance proceeds	0	1,991
Net cash used in investing activities	(65,098)	(29,096)
Cash flows from financing activities
Proceeds from revolving line of credit	110,987	235,345
Repayments of proceeds from revolving line of credit	(110,987)	(227,616)
Repurchases of common stock under share repurchase program	(15,219)	0
Payments on finance lease obligations	(1,708)
Payments on finance lease obligations		(2,059)
Principal payments on other notes	0	(25)
Other financing activities, net	(4,875)	(2,509)
Net cash (used in) provided by financing activities	(21,802)	3,136
Net decrease in cash and cash equivalents	(9,141)	(2,748)
Cash and cash equivalents
Beginning of period	150,723	11,750
End of period	141,582	9,002
Supplemental disclosure of non-cash investing and financing transactions
Acquisition-related holdback payments due at future date	2,500	1,460
Accrued repurchases of common stock under share repurchase program	$ 490	$ 0