CONSOLIDATED STATEMENT OF EQUITY - USD ($) $ in Millions	Total Stockholders' Equity Attributable to Penske Automotive Group	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Non-controlling Interest	Total
Balance at Dec. 31, 2014	$ 1,652.8		$ 690.7	$ 1,015.4	$ (53.3)	$ 28.4	$ 1,681.2
Balance (in shares) at Dec. 31, 2014		90,244,840
Increase (decrease) in stockholders' equity
Equity compensation	14.0		14.0				14.0
Equity compensation (in shares)		290,580
Repurchases of common stock	(48.9)		(48.9)				(48.9)
Repurchases of common stock (in shares)		(1,010,696)
Dividends	(84.8)			(84.8)			(84.8)
Purchase of controlling interest						22.5	22.5
Purchase of subsidiary shares from non-controlling interest						(6.1)	(6.1)
Distributions to non-controlling interest						(3.8)	(3.8)
Sale of subsidiary shares to non-controlling interest	0.2		0.2			0.5	0.7
Foreign currency translation	(61.8)				(61.8)	(1.1)	(62.9)
Other	(7.4)				(7.4)		(7.4)
Net income	326.1			326.1		4.3	330.4
Balance at Dec. 31, 2015	1,790.2		656.0	1,256.7	(122.5)	44.7	1,834.9
Balance (in shares) at Dec. 31, 2015		89,524,724
Increase (decrease) in stockholders' equity
Equity compensation	14.3		14.3				14.3
Equity compensation (in shares)		346,663
Repurchases of common stock	(173.6)		(173.6)				(173.6)
Repurchases of common stock (in shares)		(4,657,042)
Dividends	(95.1)			(95.1)			(95.1)
Purchase of subsidiary shares from non-controlling interest	(0.3)		(0.3)			(10.4)	(10.7)
Distributions to non-controlling interest						(2.4)	(2.4)
Foreign currency translation	(116.5)				(116.5)	(0.8)	(117.3)
Other	(11.0)		0.7		(11.7)	(6.0)	(17.0)
Net income	342.9			342.9		3.5	346.4
Balance at Dec. 31, 2016	1,750.9		497.1	1,504.5	(250.7)	28.6	1,779.5
Balance (in shares) at Dec. 31, 2016		85,214,345
Increase (decrease) in stockholders' equity
Equity compensation	14.9		14.9				14.9
Equity compensation (in shares)		343,385
Repurchases of common stock	(18.5)		(18.5)				(18.5)
Repurchases of common stock (in shares)		(435,710)
Issuance of common stock	32.4		32.4				32.4
Issuance of common stock (in shares)		665,487
Dividends	(108.4)			(108.4)			(108.4)
Purchase of subsidiary shares from non-controlling interest	(0.4)		(0.4)			(0.3)	(0.7)
Distributions to non-controlling interest						(1.4)	(1.4)
Foreign currency translation	96.0				96.0	3.2	99.2
Other	15.0		6.8		8.2	3.2	18.2
Net income	613.3			613.3		(0.5)	612.8
Balance at Dec. 31, 2017	$ 2,395.2		$ 532.3	$ 2,009.4	$ (146.5)	$ 32.8	$ 2,428.0
Balance (in shares) at Dec. 31, 2017		85,787,507