Condensed Consolidating Financial Information - Statement of Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Condensed consolidating statement of income
Revenues	$ 4,824.6	$ 4,482.9
Cost of sales	4,100.8	3,793.0
Gross profit	723.8	689.9
Selling, general and administrative expenses	558.9	535.8
Depreciation	20.8	18.6
Operating income	144.1	135.5
Floor plan interest expense	(12.8)	(10.3)
Other interest expense	(17.2)	(16.3)
Equity in earnings of affiliates	5.5	6.7
Income from continuing operations before income taxes	119.6	115.6
Income taxes	(39.4)	(38.8)
Income from continuing operations	80.2	76.8
(Loss) income from discontinued operations, net of tax		(0.9)
Net income	80.2	75.9
Other comprehensive income (loss), net of tax	1.2	(55.1)
Comprehensive income	81.4	20.8
Less: Comprehensive income attributable to non-controlling interests	2.4	0.1
Comprehensive income attributable to Penske Automotive Group common stockholders	79.0	20.7
Penske Automotive Group
Condensed consolidating statement of income
Selling, general and administrative expenses	6.1	6.7
Depreciation	0.4	0.4
Operating income	(6.5)	(7.1)
Floor plan interest expense	(0.8)	(0.7)
Other interest expense	(13.3)	(9.8)
Equity in earnings of affiliates	4.2	5.8
Equity in earnings of subsidiaries	135.1	127.0
Income from continuing operations before income taxes	118.7	115.2
Income taxes	(39.4)	(38.8)
Income from continuing operations	79.3	76.4
(Loss) income from discontinued operations, net of tax	(0.1)	(1.2)
Net income	79.2	75.2
Other comprehensive income (loss), net of tax	1.2	(55.1)
Comprehensive income	80.4	20.1
Less: Comprehensive income attributable to non-controlling interests	1.5	(0.6)
Comprehensive income attributable to Penske Automotive Group common stockholders	78.9	20.7
Guarantor Subsidiaries
Condensed consolidating statement of income
Revenues	2,389.2	2,348.3
Cost of sales	2,006.2	1,971.6
Gross profit	383.0	376.7
Selling, general and administrative expenses	295.8	293.2
Depreciation	10.8	10.2
Operating income	76.4	73.3
Floor plan interest expense	(6.7)	(5.2)
Other interest expense	1.3	(1.3)
Income from continuing operations before income taxes	71.0	66.8
Income taxes	(29.2)	(28.3)
Income from continuing operations	41.8	38.5
(Loss) income from discontinued operations, net of tax	0.1	(1.1)
Net income	41.9	37.4
Comprehensive income	41.9	37.4
Comprehensive income attributable to Penske Automotive Group common stockholders	41.9	37.4
Non-Guarantor Subsidiaries
Condensed consolidating statement of income
Revenues	2,435.4	2,134.6
Cost of sales	2,094.6	1,821.4
Gross profit	340.8	313.2
Selling, general and administrative expenses	257.0	235.9
Depreciation	9.6	8.0
Operating income	74.2	69.3
Floor plan interest expense	(5.3)	(4.4)
Other interest expense	(5.2)	(5.2)
Equity in earnings of affiliates	1.3	0.9
Income from continuing operations before income taxes	65.0	60.6
Income taxes	(15.6)	(14.5)
Income from continuing operations	49.4	46.1
(Loss) income from discontinued operations, net of tax	(0.1)	0.2
Net income	49.3	46.3
Other comprehensive income (loss), net of tax	(0.3)	(52.3)
Comprehensive income	49.0	(6.0)
Less: Comprehensive income attributable to non-controlling interests	2.4	0.1
Comprehensive income attributable to Penske Automotive Group common stockholders	46.6	(6.1)
Eliminations
Condensed consolidating statement of income
Equity in earnings of subsidiaries	(135.1)	(127.0)
Income from continuing operations before income taxes	(135.1)	(127.0)
Income taxes	44.8	42.8
Income from continuing operations	(90.3)	(84.2)
(Loss) income from discontinued operations, net of tax	0.1	1.2
Net income	(90.2)	(83.0)
Other comprehensive income (loss), net of tax	0.3	52.3
Comprehensive income	(89.9)	(30.7)
Less: Comprehensive income attributable to non-controlling interests	(1.5)	0.6
Comprehensive income attributable to Penske Automotive Group common stockholders	$ (88.4)	$ (31.3)