CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities
Net income	$ 89,396	$ 69,402
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization of property and equipment	32,498	30,850
Amortization of operating lease right-of-use assets	16,464	13,281
Amortization of intangibles	26,798	20,378
Amortization of deferred financing costs and debt discount	993	1,000
Provision for credit losses	1,135	3,839
Gain on sale of property and equipment	(1,405)	(592)
Noncash stock compensation	10,228	8,050
Deferred income taxes	0	(3,405)
Amortization of terminated interest rate swap		508
Changes in assets and liabilities, excluding effects of acquisitions
Accounts receivable	(23,224)	(9,624)
Inventories	(37,122)	5,983
Other assets	(8,116)	9,027
Accounts payable	14,120	(14,746)
Income taxes receivable/payable	(107)	14,192
Other liabilities	(7,594)	(4,259)
Net cash provided by operating activities	116,478	143,884
Cash flows from investing activities
Purchases of investments	0	(776)
Maturities of short term investments	0	37,473
Purchases of property and equipment	(27,898)	(25,515)
Acquisitions of businesses, net of cash acquired of $1,640 and $0 in 2021 and 2020, respectively	(94,500)	(38,825)
Proceeds from sale of property and equipment	2,219	828
Other	(1,430)	(2,662)
Net cash used in investing activities	(121,609)	(29,477)
Cash flows from financing activities
Proceeds from vehicle and equipment notes payable	20,753	17,759
Debt issuance costs	0	(157)
Principal payments on long-term debt	(19,688)	(19,801)
Principal payments on finance lease obligations	(1,573)	(1,998)
Dividends paid	(26,428)	0
Acquisition-related obligations	(2,442)	(3,896)
Repurchase of common stock	0	(15,759)
Surrender of common stock awards by employees	(5,576)	(973)
Net cash used in financing activities	(34,954)	(24,825)
Net change in cash and cash equivalents	(40,085)	89,582
Cash and cash equivalents at beginning of period	231,520	177,889
Cash and cash equivalents at end of period	191,435	267,471
Supplemental disclosures of cash flow information
Interest	23,748	24,130
Income taxes, net of refunds	27,428	13,798
Supplemental disclosure of noncash activities
Right-of-use assets obtained in exchange for operating lease obligations	23,543	18,340
Release of indemnification of acquisition-related debt	2,036	0
Property and equipment obtained in exchange for finance lease obligations	1,918	853
Seller obligations in connection with acquisition of businesses	18,987	6,965
Unpaid purchases of property and equipment included in accounts payable	$ 1,327	$ 1,229