Consolidated Balance Sheets - USD ($) $ in Millions		Dec. 31, 2018	Dec. 31, 2017
CURRENT ASSETS:
Cash and cash equivalents		$ 48.6	$ 69.2
Receivables, net		976.2	1,111.0
Inventory		3,650.5	3,365.6
Other current assets		208.7	251.7
Total Current Assets		4,884.0	4,797.5
PROPERTY AND EQUIPMENT, NET		3,155.3	2,962.7
GOODWILL	[1]	1,513.2	1,515.0
OTHER INTANGIBLE ASSETS, NET		595.4	586.8
OTHER ASSETS		517.2	409.5
Total Assets		10,665.1	10,271.5
CURRENT LIABILITIES:
Vehicle floorplan payable		3,997.7	3,806.9
Accounts payable		306.2	309.8
Commercial paper		630.0	330.0
Current maturities of long-term debt		44.3	414.5
Other current liabilities		679.9	774.5
Total Current Liabilities		5,658.1	5,635.7
LONG-TERM DEBT, NET OF CURRENT MATURITIES		1,926.2	1,959.2
DEFERRED INCOME TAXES		89.8	71.9
OTHER LIABILITIES		275.0	235.4
COMMITMENTS AND CONTINGENCIES (Note 18)
SHAREHOLDERS' EQUITY:
Preferred stock, par value $0.01 per share; 5,000,000 shares authorized; none issued		0.0	0.0
Common stock, par value $0.01 per share; 1,500,000,000 shares authorized; 102,562,149 shares issued at December 31, 2018, and December 31, 2017, including shares held in treasury		1.0	1.0
Additional paid-in capital		20.8	4.0
Retained earnings		3,238.3	2,832.2
Treasury stock, at cost; 12,540,065 and 11,002,298 shares held, respectively		(544.1)	(467.9)
Total Shareholders' Equity		2,716.0	2,369.3
Total Liabilities and Shareholders' Equity		10,665.1	10,271.5
Trade [Member]
CURRENT LIABILITIES:
Vehicle floorplan payable		2,388.0	2,179.1
Non-Trade [Member]
CURRENT LIABILITIES:
Vehicle floorplan payable		$ 1,609.7	$ 1,627.8

[1] Net of accumulated impairment losses of $1.47 billion associated with our single reporting unit (prior to September 30, 2008, our reporting unit structure was comprised of a single reporting unit) and $140.0 million associated with our Domestic reporting unit, both of which were recorded during the year ended December 31, 2008.