CONSOLIDATED CONDENSED 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, 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 | ASC 606	6.6			6.6			6.6
Equity compensation	9.0		9.0				9.0
Equity compensation (in shares)		330,186
Repurchases of common stock	(55.8)		(55.8)				(55.8)
Repurchases of common stock (in shares)		(1,252,624)
Dividends	(59.0)			(59.0)			(59.0)
Purchase of subsidiary shares from non-controlling interest	(1.4)		(1.4)			(3.1)	(4.5)
Distributions to non-controlling interest						(0.7)	(0.7)
Foreign currency translation	(36.5)				(36.5)	(1.1)	(37.6)
Other	(3.6)		(0.2)		(3.4)	0.4	(3.2)
Net income	242.7			242.7		0.3	243.0
Balance at Jun. 30, 2018	2,497.2		483.9	2,199.7	(186.4)	28.6	2,525.8
Balance (in shares) at Jun. 30, 2018		84,865,069
Balance at Mar. 31, 2018	2,465.4		485.2	2,094.9	(114.7)	29.0	2,494.4
Balance (in shares) at Mar. 31, 2018		84,975,410
Increase (decrease) in stockholders' equity
Equity compensation	4.5		4.5				4.5
Equity compensation (in shares)		9,267
Repurchases of common stock	(5.8)		(5.8)				(5.8)
Repurchases of common stock (in shares)		(119,608)
Dividends	(29.8)			(29.8)			(29.8)
Distributions to non-controlling interest						(0.6)	(0.6)
Foreign currency translation	(67.2)				(67.2)	(1.1)	(68.3)
Other	(4.5)				(4.5)	0.7	(3.8)
Net income	134.6			134.6		0.6	135.2
Balance at Jun. 30, 2018	2,497.2		483.9	2,199.7	(186.4)	28.6	2,525.8
Balance (in shares) at Jun. 30, 2018		84,865,069
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
Increase (decrease) in stockholders' equity
Adoption of ASC | ASC 842	5.0			5.0			5.0
Equity compensation	9.3		9.3				9.3
Equity compensation (in shares)		374,549
Repurchases of common stock	(130.6)		(130.6)				(130.6)
Repurchases of common stock (in shares)		(2,965,214)
Dividends	(64.5)			(64.5)			(64.5)
Purchase of subsidiary shares from non-controlling interest						(4.8)	(4.8)
Distributions to non-controlling interest						(0.4)	(0.4)
Foreign currency translation	(9.6)				(9.6)	(0.2)	(9.8)
Other	3.8				3.8	0.6	4.4
Net income	218.0			218.0		(0.3)	217.7
Balance at Jun. 30, 2019	2,640.5		356.5	2,524.3	(240.3)	20.5	2,661.0
Balance (in shares) at Jun. 30, 2019		81,956,305
Balance at Mar. 31, 2019	2,641.2		428.1	2,438.8	(225.7)	19.7	2,660.9
Balance (in shares) at Mar. 31, 2019		83,651,509
Increase (decrease) in stockholders' equity
Equity compensation	4.6		4.6				4.6
Equity compensation (in shares)		11,662
Repurchases of common stock	(76.2)		(76.2)				(76.2)
Repurchases of common stock (in shares)		(1,706,866)
Dividends	(32.3)			(32.3)			(32.3)
Distributions to non-controlling interest						(0.3)	(0.3)
Foreign currency translation	(16.6)				(16.6)	0.1	(16.5)
Other	2.0				2.0	0.3	2.3
Net income	117.8			117.8		0.7	118.5
Balance at Jun. 30, 2019	$ 2,640.5		$ 356.5	$ 2,524.3	$ (240.3)	$ 20.5	$ 2,661.0
Balance (in shares) at Jun. 30, 2019		81,956,305