CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue:
Total revenues	$ 21,386.9	$ 20,118.5	$ 19,284.9
Cost of sales:
Total cost of sales	18,164.4	17,151.9	16,417.4
Gross profit	3,222.5	2,966.6	2,867.5
Selling, general and administrative expenses	2,516.0	2,302.0	2,223.0
Depreciation	95.1	89.7	78.0
Operating income	611.4	574.9	566.5
Floor plan interest expense	(63.4)	(50.9)	(44.5)
Other interest expense	(107.4)	(85.4)	(69.4)
Equity in earnings of affiliates	107.6	69.5	39.3
Income from continuing operations before income taxes	548.2	508.1	491.9
Income taxes	64.8	(160.7)	(158.0)
Income from continuing operations	613.0	347.4	333.9
Loss from discontinued operations, net of tax	(0.2)	(1.0)	(3.5)
Net income	612.8	346.4	330.4
Less: (Loss) income attributable to non-controlling interests	(0.5)	3.5	4.3
Net income attributable to Penske Automotive Group common stockholders	$ 613.3	$ 342.9	$ 326.1
Basic earnings per share attributable to Penske Automotive Group common stockholders:
Continuing operations (in dollars per share)	$ 7.14	$ 4.00	$ 3.67
Discontinued operations (in dollars per share)	0.00	(0.01)	(0.04)
Net income attributable to Penske Automotive Group common stockholders (in dollars per share)	$ 7.14	$ 3.99	$ 3.63
Shares used in determining basic earnings per share (in shares)	85,877,227	86,000,754	89,759,626
Diluted earnings per share attributable to Penske Automotive Group common stockholders:
Continuing operations (in dollars per share)	$ 7.14	$ 4.00	$ 3.67
Discontinued operations (in dollars per share)	0.00	(0.01)	(0.04)
Net income attributable to Penske Automotive Group common stockholders (in dollars per share)	$ 7.14	$ 3.99	$ 3.63
Shares used in determining diluted earnings per share (in shares)	85,877,227	86,000,754	89,759,626
Amounts attributable to Penske Automotive Group common stockholders:
Income from continuing operations	$ 613.0	$ 347.4	$ 333.9
Less: (Loss) income attributable to non-controlling interests	(0.5)	3.5	4.3
Income from continuing operations, net of tax	613.5	343.9	329.6
Loss from discontinued operations, net of tax	(0.2)	(1.0)	(3.5)
Net income attributable to Penske Automotive Group common stockholders	$ 613.3	$ 342.9	$ 326.1
Cash dividends per share (in dollars per share)	$ 1.26	$ 1.1	$ 0.94
Retail Automotive Dealership
Revenue:
Total revenues	$ 19,824.3	$ 18,673.2	$ 17,896.3
Cost of sales:
Total cost of sales	16,899.5	15,968.4	15,288.3
Retail Commercial Truck Dealership
Revenue:
Total revenues	1,048.0	1,000.7	944.1
Cost of sales:
Total cost of sales	882.2	857.8	797.1
Commercial Vehicle Distribution and Other
Revenue:
Total revenues	514.6	444.6	444.5
Cost of sales:
Total cost of sales	$ 382.7	$ 325.7	$ 332.0