Unaudited Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES:
Net income	$ 230.1	$ 292.3
Adjustments to reconcile net income to net cash provided by operating activities:
Loss from discontinued operations	0.2	0.8
Depreciation and amortization	149.0	133.7
Amortization of debt issuance costs and accretion of debt discounts	3.5	3.9
Stock-based compensation expense	22.9	28.1
Deferred income tax provision (benefit)	(25.0)	36.8
Net gain related to business/property dispositions	(2.4)	(19.1)
Goodwill impairment	318.3	0.0
Franchise rights impairment	57.5	9.6
Non-cash impairment charges	11.4	2.2
Unrealized gain on equity investment	(212.7)	0.0
Other	(4.0)	(4.1)
(Increase) decrease, net of effects from business acquisitions and divestitures:
Receivables	232.7	143.6
Inventory	827.4	319.1
Other assets	81.6	34.1
Increase (decrease), net of effects from business acquisitions and divestitures:
Vehicle floorplan payable - trade, net	(661.8)	(288.2)
Accounts payable	57.5	(37.0)
Other liabilities	78.1	9.7
Net cash provided by continuing operations	1,164.3	665.5
Net cash provided by discontinued operations	0.0	0.0
Net cash provided by operating activities	1,164.3	665.5
CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES:
Purchases of property and equipment	(113.1)	(186.3)
Proceeds from assets held for sale	8.2	6.5
Insurance recoveries on property and equipment	1.9	3.3
Cash received from business divestitures, net of cash relinquished	2.2	67.2
Cash used in business acquisitions, net of cash acquired	(0.4)	(4.7)
Investment in equity security	(50.0)	0.0
Other	(0.4)	0.5
Net cash used in continuing operations	(151.6)	(113.5)
Net cash used in discontinued operations	0.0	0.0
Net cash used in investing activities	(151.6)	(113.5)
CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES:
Repurchases of common stock	(80.0)	(44.7)
Proceeds from 4.75% Senior Notes due 2030	497.4	0.0
Payment of 5.5% Senior Notes due 2020	(350.0)	0.0
Proceeds from revolving credit facility	1,110.0	0.0
Payments of revolving credit facility	(1,110.0)	0.0
Net payments of commercial paper	(170.0)	(330.0)
Payment of debt issuance costs	(11.0)	0.0
Net payments of vehicle floorplan payable - non-trade	(609.7)	(180.0)
Payments of other debt obligations	(4.6)	(6.2)
Proceeds from the exercise of stock options	31.5	8.0
Payments of tax withholdings for stock-based awards	(8.2)	(3.0)
Net cash used in continuing operations	(704.6)	(555.9)
Net cash used in discontinued operations	0.0	0.0
Net cash used in financing activities	(704.6)	(555.9)
INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH	308.1	(3.9)
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH at beginning of period	42.5	49.4
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH at end of period	$ 350.6	$ 45.5