CONSOLIDATED CONDENSED STATEMENTS OF EQUITY - USD ($) $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment	Total Penske Automotive Group Stockholders’ Equity	Total Penske Automotive Group Stockholders’ Equity Cumulative Effect, Period of Adoption, Adjustment	Voting and Non-voting Common Stock	Additional Paid-in Capital	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Income (Loss)	Non-controlling Interest
Balance (in shares) at Dec. 31, 2020					80,392,662
Beginning balance at Dec. 31, 2020	$ 3,326.1		$ 3,302.5		$ 0.0	$ 311.8	$ 3,151.3		$ (160.6)	$ 23.6
Increase (decrease) in stockholders' equity
Equity compensation (in shares)					433,481
Equity compensation	13.1		13.1			13.1
Repurchases of common stock (in shares)					(495,307)
Repurchases of common stock	(40.9)		(40.9)			(40.9)
Dividends	(70.2)		(70.2)				(70.2)
Interest rate swaps	3.5		3.5						3.5
Distributions to non-controlling interest	(1.4)									(1.4)
Foreign currency translation	1.9		2.2						2.2	(0.3)
Other	7.1		7.1						7.1	0.0
Net income	523.5		521.4				521.4			2.1
Balance (in shares) at Jun. 30, 2021					80,330,836
Ending balance at Jun. 30, 2021	3,762.7		3,738.7		$ 0.0	284.0	3,602.5		(147.8)	24.0
Balance (in shares) at Mar. 31, 2021					80,827,657
Beginning balance at Mar. 31, 2021	3,484.7		3,462.2		$ 0.0	318.4	3,299.2		(155.4)	22.5
Increase (decrease) in stockholders' equity
Equity compensation (in shares)					(1,514)
Equity compensation	6.5		6.5			6.5
Repurchases of common stock (in shares)					(495,307)
Repurchases of common stock	(40.9)		(40.9)			(40.9)
Dividends	(35.6)		(35.6)				(35.6)
Interest rate swaps	(0.4)		(0.4)						(0.4)
Distributions to non-controlling interest	(0.2)									(0.2)
Foreign currency translation	1.8		1.6						1.6	0.2
Other	6.4		6.4						6.4
Net income	340.4		338.9				338.9			1.5
Balance (in shares) at Jun. 30, 2021					80,330,836
Ending balance at Jun. 30, 2021	3,762.7		3,738.7		$ 0.0	284.0	3,602.5		(147.8)	24.0
Balance (in shares) at Dec. 31, 2021					77,574,172
Beginning balance at Dec. 31, 2021	$ 4,095.0	$ (121.6)	4,070.0	$ (121.6)	$ 0.0	42.2	4,196.6	$ (121.6)	(168.8)	25.0
Increase (decrease) in stockholders' equity
Accounting standards update	Accounting Standards Update 2016-02 [Member]
Equity compensation (in shares)					307,846
Equity compensation	$ 14.6		14.6			14.6
Repurchases of common stock (in shares)					(2,866,556)
Repurchases of common stock	(292.6)		(292.6)			(56.8)		$ (235.8)
Dividends	(74.4)		(74.4)				(74.4)
Interest rate swaps	0.0
Distributions to non-controlling interest	(2.7)									(2.7)
Foreign currency translation	(148.8)		(147.6)						(147.6)	(1.2)
Other	4.5		4.5						4.5
Net income	745.4		741.9				741.9			3.5
Balance (in shares) at Jun. 30, 2022					75,015,462
Ending balance at Jun. 30, 2022	4,219.4		4,194.8		$ 0.0	0.0	4,506.7		(311.9)	24.6
Balance (in shares) at Mar. 31, 2022					76,658,405
Beginning balance at Mar. 31, 2022	4,164.4		4,138.8		$ 0.0	0.0	4,336.9		(198.1)	25.6
Increase (decrease) in stockholders' equity
Equity compensation (in shares)					20,164
Equity compensation	7.2		7.2			7.2
Repurchases of common stock (in shares)					(1,663,107)
Repurchases of common stock	(173.4)		(173.4)			(7.2)	(166.2)
Dividends	(38.0)		(38.0)				(38.0)
Interest rate swaps	0.0
Distributions to non-controlling interest	(2.1)									(2.1)
Foreign currency translation	(120.3)		(119.5)						(119.5)	(0.8)
Other	5.7		5.7						5.7
Net income	375.9		374.0				374.0			1.9
Balance (in shares) at Jun. 30, 2022					75,015,462
Ending balance at Jun. 30, 2022	$ 4,219.4		$ 4,194.8		$ 0.0	$ 0.0	$ 4,506.7		$ (311.9)	$ 24.6