CONSOLIDATED STATEMENTS OF CASH FLOWS $ in Millions	12 Months Ended
	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Cash flows from operating activities
Net income	$ 256.6	$ 243.7	$ 223.4
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization of property and equipment	59.1	52.2	47.3
Amortization of operating lease right-of-use assets	32.9	29.0	26.6
Amortization of intangibles	42.5	44.5	43.8
Amortization of deferred financing costs and debt discount	1.6	1.9	1.9
Provision for credit losses	6.0	6.3	4.1
Write-off of debt issuance costs	1.5	0.9	0.0
Gain on sale of property and equipment	(1.9)	(1.9)	(1.4)
Noncash stock compensation	19.4	15.9	13.8
Asset impairment	4.9	0.0	0.0
Gains on acquisition earnouts	0.0	0.0	(16.1)
Deferred income taxes	1.7	0.5	7.1
Other, net	(13.1)	(12.2)	(0.1)
Changes in assets and liabilities, excluding effects of acquisitions
Accounts receivable	(10.8)	(25.1)	(76.5)
Inventories	(26.3)	16.5	(16.5)
Proceeds from termination of interest rate swap agreements	0.0	0.0	25.5
Other assets	(7.9)	(11.0)	(2.6)
Accounts payable	(18.8)	5.1	9.6
Income taxes receivable/payable	3.4	(5.7)	3.2
Other liabilities	(10.8)	(20.4)	(15.2)
Net cash provided by operating activities	340.0	340.2	277.9
Cash flows from investing activities
Purchases of investments	0.0	0.0	(344.4)
Maturities of short term investments	0.0	0.0	345.0
Purchases of property and equipment	(88.6)	(61.6)	(45.6)
Acquisitions of businesses, net of cash acquired of $—, $— and $0.5 in 2024, 2023 and 2022, respectively	(88.6)	(59.6)	(113.5)
Proceeds from sale of property and equipment	2.9	2.7	2.0
Settlements with interest rate swap counterparties	17.5	16.7	4.0
Other, net	(2.3)	(1.6)	(6.2)
Net cash used in investing activities	(159.1)	(103.4)	(158.7)
Cash flows from financing activities
Proceeds from term loan (Note 8)	186.0	0.0	0.0
Payments on term loan (Note 8)	(179.8)	(5.0)	(5.0)
Proceeds from vehicle and equipment notes payable	28.7	38.7	30.9
Debt issuance costs	(1.5)	(0.5)	(0.6)
Principal payments on long-term debt	(30.0)	(29.5)	(30.2)
Principal payments on finance lease obligations	(3.0)	(2.9)	(2.3)
Acquisition-related obligations	(2.2)	(4.7)	(11.1)
Dividends paid	(84.7)	(63.1)	(62.7)
Repurchase of common stock	(145.3)	(6.3)	(137.6)
Surrender of common stock awards by employees	(8.0)	(6.6)	(4.5)
Net cash used in financing activities	(239.8)	(79.9)	(223.1)
Net change in cash and cash equivalents	(58.9)	156.9	(103.9)
Cash and cash equivalents at beginning of period	386.5	229.6	333.5
Cash and cash equivalents at end of period	327.6	386.5	229.6
Supplemental disclosures of cash flow information
Interest	43.7	42.5	40.3
Income taxes, net of refunds	83.6	92.5	69.1
Supplemental disclosure of noncash activities
Right-of-use assets obtained in exchange for operating lease obligations	49.4	30.7	32.7
Release of indemnification of acquisition-related debt	0.0	0.0	1.0
Property and equipment obtained in exchange for finance lease obligations	2.0	3.3	6.2
Seller obligations in connection with acquisition of businesses	5.6	9.3	27.0
Unpaid purchases of property and equipment included in accounts payable	5.7	3.1	0.9
Accrued excise tax on common stock repurchases	$ 1.3	$ 0.0	$ 0.0