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, 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
Increase (decrease) in stockholders' equity
Adoption of ASC 606 (Note 1) | ASC 606	6.6			6.6			6.6
Equity compensation	16.1		16.1				16.1
Equity compensation (in shares)		346,957
Repurchases of common stock	(68.9)		(68.9)				(68.9)
Repurchases of common stock (in shares)		(1,587,494)
Dividends	(121.2)			(121.2)			(121.2)
Purchase of subsidiary shares from non-controlling interest	(1.5)		(1.5)			(5.4)	(6.9)
Distributions to non-controlling interest						(0.9)	(0.9)
Foreign currency translation	(74.3)				(74.3)	(1.5)	(75.8)
Other	(13.9)		(0.2)		(13.7)	1.3	(12.6)
Net income	471.0			471.0		(0.7)	470.3
Balance at Dec. 31, 2018	$ 2,609.1		$ 477.8	$ 2,365.8	$ (234.5)	$ 25.6	$ 2,634.7
Balance (in shares) at Dec. 31, 2018		84,546,970