CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Operating Activities:
Net income	$ 937.9	$ 973.4	$ 1,114.2
Adjustments to reconcile net income to net cash from operating activities:
Depreciation	172.3	161.3	143.7
Earnings of equity method investments, net of distributions	(120.2)	(127.9)	(174.6)
Deferred income taxes	66.2	(13.0)	101.8
Stock-based compensation	30.2	29.4	28.1
Goodwill impairment charges	0.0	0.0	40.7
Gain on sale of dealership	(52.3)	0.0	0.0
Changes in operating assets and liabilities:
Accounts receivable	1.6	128.1	(201.6)
Inventories	52.1	(157.2)	(725.9)
Other current assets	(14.8)	(43.5)	(34.5)
Floor plan notes payable	(89.7)	273.3	719.0
Accounts payable and accrued expenses	(53.0)	40.2	(13.5)
Other	44.8	(33.5)	147.8
Net cash provided by operating activities	975.1	1,230.6	1,145.2
Investing Activities:
Purchases of property, equipment, and improvements	(324.6)	(377.8)	(386.0)
Proceeds from sale of dealerships	119.9	82.1	0.0
Proceeds from sale of property and equipment	27.5	26.2	30.7
Proceeds from sale of equity method investment	16.0	20.7	0.0
Acquisitions net, including repayment of sellers' floor plan notes payable of $0.0, $212.5, and $24.3, respectively	(21.5)	(786.2)	(214.9)
Other	7.7	(10.9)	(12.8)
Net cash used in investing activities	(175.0)	(1,045.9)	(583.0)
Financing Activities:
Proceeds from borrowings under revolving U.S. credit agreement and mortgage facilities	5,782.8	4,301.4	3,150.3
Repayments under revolving U.S. credit agreement and mortgage facilities	(5,166.6)	(4,182.7)	(3,227.8)
Repayment of 3.50% senior subordinated notes	(550.0)
Net cash borrowings of other debt	59.7	113.3	73.2
Repayments of related party promissory note	(4.3)	0.0	0.0
Net (repayments) borrowings of floor plan notes payable — non-trade	(4.7)	(15.7)	59.9
Repurchases of common stock	(159.1)	(58.7)	(358.7)
Payments of tax withholding for stock-based compensation	(22.9)	(18.8)	(23.5)
Dividends	(343.8)	(274.4)	(189.1)
PMG distributions to partners	(52.5)	(36.6)	(54.7)
PMG common control transaction	(363.6)	0.0	0.0
Payment of debt issuance costs	(0.5)	(1.0)	(2.1)
Purchase of subsidiary shares from non-controlling interest	0.0	(16.7)	0.0
Other	0.0	(11.7)	0.1
Net cash used in financing activities	(825.5)	(201.6)	(572.4)
Effect of exchange rate changes on cash and cash equivalents	6.5	(2.1)	(0.3)
Net change in cash and cash equivalents	(18.9)	(19.0)	(10.5)
Cash and cash equivalents, beginning of period	83.6	102.6	113.1
Cash and cash equivalents, end of period	64.7	83.6	102.6
Cash paid for:
Interest	274.2	275.1	216.2
Income taxes	271.5	317.4	288.1
Non-cash activities:
Receivable from sale of investment	0.0	10.4	0.0
Note payable from purchase of common control entity	$ 155.8	$ 0.0	$ 0.0