CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities
Net income	$ 17,291	$ 15,988
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization of property and equipment	10,663	10,374
Amortization of operating lease right-of-use assets	5,050	4,207
Amortization of intangibles	8,396	6,680
Amortization of deferred financing costs and debt discount	331	325
Provision for credit losses	127	1,298
Gain on sale of property and equipment	(252)	(35)
Noncash stock compensation	3,196	2,681
Amortization of terminated interest rate swap	798	0
Changes in assets and liabilities, excluding effects of acquisitions
Accounts receivable	1,056	(1,000)
Inventories	(7,644)	1,411
Other assets	(1,794)	6,933
Accounts payable	524	(8,308)
Income taxes receivable/payable	4,633	5,649
Other liabilities	(4,757)	(10,291)
Net cash provided by operating activities	37,618	35,912
Cash flows from investing activities
Purchases of investments	0	(776)
Maturities of short term investments	0	12,275
Purchases of property and equipment	(10,846)	(9,919)
Payments to Acquire Businesses, Net of Cash Acquired	(41,930)	(8,501)
Proceeds from sale of property and equipment	389	162
Other	(5)	(1,340)
Net cash used in investing activities	(52,392)	(8,099)
Cash flows from financing activities
Proceeds from vehicle and equipment notes payable	7,808	7,094
Debt issuance costs	0	(22)
Principal payments on long-term debt	(6,481)	(6,711)
Principal payments on finance lease obligations	(530)	(738)
Dividends paid	(8,786)	0
Acquisition-related obligations	(1,414)	(2,378)
Repurchase of common stock	0	(15,759)
Net cash used in financing activities	(9,403)	(18,514)
Net change in cash and cash equivalents	(24,177)	9,299
Cash and cash equivalents at beginning of period	231,520	177,889
Cash and cash equivalents at end of period	207,343	187,188
Supplemental disclosures of cash flow information
Interest	10,839	9,798
Income taxes, net of refunds	1,474	37
Supplemental disclosure of noncash activities
Right-of-use assets obtained in exchange for operating lease obligations	5,679	5,612
Property and equipment obtained in exchange for finance lease obligations	268	343
Seller obligations in connection with acquisition of businesses	5,959	2,570
Unpaid purchases of property and equipment included in accounts payable	$ 1,043	$ 1,346