CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Activities:
Net income	$ 1,386.2	$ 1,192.7	$ 545.3
Adjustments to reconcile net income to net cash from continuing operating activities:
Depreciation	127.3	121.5	115.5
Loss on investment	0.0	11.4	0.0
Earnings of equity method investments	(183.3)	(234.9)	(115.0)
Income from discontinued operations, net of tax	0.0	(1.3)	(0.4)
Deferred income taxes	124.2	184.8	194.3
Debt redemption costs	0.0	17.0	8.6
Changes in operating assets and liabilities:
Accounts receivable	(192.9)	75.6	152.7
Inventories	(444.4)	402.6	805.4
Floor plan notes payable	487.1	(628.6)	(611.0)
Accounts payable and accrued expenses	81.7	139.0	125.0
Other	73.1	12.2	(18.9)
Net cash provided by continuing operating activities	1,459.0	1,292.0	1,201.5
Investing Activities:
Purchases of property, equipment, and improvements	(282.5)	(248.9)	(185.9)
Proceeds from sale of dealerships	13.1	4.3	40.6
Proceeds from sale of property and equipment	32.3	54.9	19.8
Acquisitions net, including repayment of sellers' floor plan notes payable of $51.3, $43.0, and $0.0, respectively	(393.4)	(431.8)	0.0
Other	(11.2)	(1.6)	(11.0)
Net cash used in continuing investing activities	(641.7)	(623.1)	(136.5)
Financing Activities:
Proceeds from borrowings under U.S. credit agreement revolving credit line	2,101.0	1,856.0	1,797.0
Repayments under U.S. credit agreement revolving credit line	(2,101.0)	(1,964.0)	(1,734.0)
Net borrowings (repayments) of other long-term debt	160.1	(104.2)	(144.4)
Net borrowings (repayments) of floor plan notes payable — non-trade	82.9	38.9	(230.2)
Payments for contingent consideration	0.0	0.0	(31.6)
Repurchases of common stock	(869.3)	(280.6)	(29.4)
Dividends	(154.1)	(142.5)	(68.1)
Payment of debt issuance costs	(0.3)	(6.3)	(8.1)
Other	(17.3)	(12.8)	(5.1)
Net cash used in continuing financing activities	(798.0)	(615.5)	(1,053.9)
Discontinued operations:
Net cash provided by discontinued operating activities	0.0	1.3	0.3
Net cash provided by discontinued operations	0.0	1.3	0.3
Effect of exchange rate changes on cash and cash equivalents	(13.5)	(3.5)	10.0
Net change in cash and cash equivalents	5.8	51.2	21.4
Cash and cash equivalents, beginning of period	100.7	49.5	28.1
Cash and cash equivalents, end of period	106.5	100.7	49.5
Cash paid for:
Interest	112.8	95.3	168.5
Income taxes	343.4	160.1	17.9
3.50% senior subordinated notes due 2025
Financing Activities:
Issuance of senior subordinated notes	0.0	0.0	550.0
3.75% senior subordinated notes due 2029
Financing Activities:
Issuance of senior subordinated notes	0.0	500.0	0.0
3.75% senior subordinated notes due 2020
Financing Activities:
Repayment of senior subordinated notes	0.0	0.0	(300.0)
5.375% senior subordinated notes due 2024
Financing Activities:
Repayment of senior subordinated notes	0.0	0.0	(300.0)
5.50% senior subordinated notes due 2026
Financing Activities:
Repayment of senior subordinated notes	0.0	(500.0)	0.0
5.75% senior subordinated notes due 2022
Financing Activities:
Repayment of senior subordinated notes	$ 0.0	$ 0.0	$ (550.0)