Consolidated Income Statements (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenue:
TOTAL REVENUE	$ 17,517.6	$ 15,667.5	$ 13,832.3
Cost of Sales:
TOTAL COST OF SALES (excluding depreciation shown below)	14,757.7	13,181.3	11,528.3
Gross Profit:
TOTAL GROSS PROFIT	2,759.9	2,486.2	2,304.0
Selling, general & administrative expenses	1,935.0	1,749.3	1,649.4
Depreciation and amortization	95.3	87.3	83.7
Franchise rights impairment	0	4.2	0
Other expenses (income), net	(10.7)	0.1	(1.1)
OPERATING INCOME	740.3	645.3	572.0
Non-operating income (expense) items:
Floorplan interest expense	(53.4)	(45.5)	(42.7)
Other interest expense	(88.3)	(86.9)	(66.0)
Loss on debt extinguishment	0	0	(2.2)
Interest income	0.2	0.3	0.7
Other income (losses), net	5.6	3.6	(0.5)
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	604.4	516.8	461.3
Income tax provision	228.6	199.5	177.1
NET INCOME FROM CONTINUING OPERATIONS	375.8	317.3	284.2
Loss from discontinued operations, net of income taxes	(0.9)	(0.9)	(2.8)
NET INCOME	374.9	316.4	281.4
BASIC EARNINGS (LOSS) PER SHARE:
Continuing operations	$ 3.10	$ 2.56	$ 1.96
Discontinued operations	$ (0.01)	$ (0.01)	$ (0.02)
Net income	$ 3.09	$ 2.56	$ 1.94
Weighted average common shares outstanding	121.3	123.8	144.8
DILUTED EARNINGS (LOSS) PER SHARE:
Continuing operations	$ 3.05	$ 2.52	$ 1.93
Discontinued operations	$ (0.01)	$ (0.01)	$ (0.02)
Net income	$ 3.04	$ 2.52	$ 1.91
Weighted average common shares outstanding	123.3	125.8	147.3
COMMON SHARES OUTSTANDING, net of treasury stock, at period end	120.9	120.9	135.8
New Vehicle [Member]
Revenue:
TOTAL REVENUE	9,949.6	8,906.2	7,498.9
Cost of Sales:
TOTAL COST OF SALES (excluding depreciation shown below)	9,333.2	8,326.7	6,951.2
Gross Profit:
TOTAL GROSS PROFIT	616.4	579.5	547.7
Used Vehicle [Member]
Revenue:
TOTAL REVENUE	4,127.4	3,714.3	3,512.8
Cost of Sales:
TOTAL COST OF SALES (excluding depreciation shown below)	3,797.7	3,415.1	3,228.0
Gross Profit:
TOTAL GROSS PROFIT	329.7	299.2	284.8
Parts and Service [Member]
Revenue:
TOTAL REVENUE	2,597.4	2,399.2	2,293.1
Cost of Sales:
TOTAL COST OF SALES (excluding depreciation shown below)	1,491.6	1,391.2	1,323.0
Gross Profit:
TOTAL GROSS PROFIT	1,105.8	1,008.0	970.1
Finance and Insurance, Net [Member]
Revenue:
TOTAL REVENUE	674.0	571.2	474.5
Gross Profit:
TOTAL GROSS PROFIT	674.0	571.2	474.5
Other Goods and Services [Member]
Revenue:
TOTAL REVENUE	169.2	76.6	53.0
Cost of Sales:
TOTAL COST OF SALES (excluding depreciation shown below)	135.2	48.3	26.1
Gross Profit:
TOTAL GROSS PROFIT	$ 34.0	$ 28.3	$ 26.9