CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
REVENUE:
New vehicle	$ 964.0	$ 821.3	$ 2,720.7	$ 2,378.8
Used vehicle	493.0	457.0	1,474.0	1,319.2
Parts and service	190.6	168.3	555.5	495.9
Finance and insurance, net	68.8	59.0	197.6	170.8
TOTAL REVENUE	1,716.4	1,505.6	4,947.8	4,364.7
COST OF SALES:
New vehicle	911.7	772.1	2,568.2	2,232.4
Used vehicle	459.6	425.8	1,371.6	1,220.6
Parts and service	72.4	63.1	207.6	189.1
TOTAL COST OF SALES	1,443.7	1,261.0	4,147.4	3,642.1
GROSS PROFIT	272.7	244.6	800.4	722.6
OPERATING EXPENSES:
Selling, general and administrative	188.8	171.5	546.4	500.5
Depreciation and amortization	7.5	6.7	22.0	19.4
Other operating (income) expense, net	(0.2)	0.3	0.1	0.2
INCOME FROM OPERATIONS	76.6	66.1	231.9	202.5
OTHER (INCOME) EXPENSES:
Floor plan interest expense	4.1	3.0	12.0	9.3
Other interest expense, net	10.7	9.6	31.5	28.2
Swap interest expense	1.0	0.5	2.0	1.5
Gain on divestitures	(21.4)	0.0	(21.4)	0.0
Total other (income) expenses, net	(5.6)	13.1	24.1	39.0
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	82.2	53.0	207.8	163.5
Income tax expense	31.0	20.6	79.6	63.4
INCOME FROM CONTINUING OPERATIONS	51.2	32.4	128.2	100.1
Discontinued operations, net of tax	(0.1)	0.1	(0.1)	(0.3)
NET INCOME	$ 51.1	$ 32.5	$ 128.1	$ 99.8
Basic—
Continuing operations (in dollars per share)	$ 1.98	$ 1.09	$ 4.80	$ 3.31
Discontinued operations (in dollars per share)	(0.01)	0.00	0.00	(0.01)
Net income (in dollars per share)	1.97	1.09	4.80	3.30
Diluted—
Continuing operations (in dollars per share)	1.96	1.08	4.77	3.29
Discontinued operations (in dollars per share)	0.00	0.00	(0.01)	(0.01)
Net income (in dollars per share)	$ 1.96	$ 1.08	$ 4.76	$ 3.28
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING:
Basic (in shares)	25.9	29.8	26.7	30.2
Restricted stock (in shares)	0.1	0.1	0.1	0.1
Performance share units (in shares)	0.1	0.1	0.1	0.1
Diluted (in shares)	26.1	30.0	26.9	30.4