CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities
Net income	$ 110,546	$ 89,646
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation expense	45,702	39,722
Amortization of intangible assets	15,045	13,237
Amortization of debt issuance costs	952	1,124
Deferred income taxes	7,418	4,857
Non-cash stock compensation expense	11,110	9,177
Gain on sale of property, equipment and real estate	(518)	(1,839)
Other non-cash adjustments	2,395	2,314
Change in assets and liabilities, net of effects of acquisitions
Accounts receivable, net of allowances	(68,365)	(24,068)
Inventories	(81,004)	(494)
Accounts payable	121,405	68,456
Other assets and liabilities	42,508	(3,715)
Net cash provided by operating activities	207,194	198,417
Cash flows from investing activities
Purchases of businesses, net of cash acquired	0	(85,780)
Purchases of property, equipment and real estate	(71,037)	(67,582)
Proceeds from sale of property, equipment and real estate	1,258	4,444
Insurance proceeds	0	107
Net cash used in investing activities	(69,779)	(148,811)
Cash flows from financing activities
Proceeds from revolving credit facility	144,000	110,987
Repayments of proceeds from revolving credit facility	(144,000)	(110,987)
Repurchases of common stock under share repurchase program	(1,416)	(16,446)
Payments on finance lease obligations	(4,613)	(5,094)
Other financing activities, net	(10,661)	(5,530)
Net cash used in financing activities	(16,690)	(27,070)
Net increase in cash and cash equivalents	120,725	22,536
Cash and cash equivalents
Beginning of period	165,496	150,723
End of period	286,221	173,259
Supplemental disclosure of non-cash transactions
Accrued purchases of property and equipment	4,807	4,484
Acquisition-related holdback payments due at future date	3,462	4,527
Assets acquired under finance lease obligations	0	5,789
Right-of-use assets obtained in exchange for operating lease obligations	$ 13,636	$ 34,836