CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 1,192.7	$ 545.3	$ 435.1
Other comprehensive income (loss):
Foreign currency translation adjustment	(39.8)	51.3	21.9
Unrealized gain (loss) on interest rate swaps:
Unrealized gain (loss) arising during the period, net of tax (provision) benefit of ($1.2), $1.3, and $0.0, respectively	4.4	(3.6)	0.0
Reclassification adjustment for (gain) loss included in floor plan interest expense, net of tax provision (benefit) of $0.3, ($0.2), and $0.0, respectively	(1.2)	0.4	0.0
Unrealized gain (loss) on interest rate swaps, net of tax	3.2	(3.2)	0.0
Other adjustments to comprehensive income (loss), net	27.5	(5.2)	9.5
Other comprehensive income (loss), net of tax	(9.1)	42.9	31.4
Comprehensive income	1,183.6	588.2	466.5
Less: Comprehensive income (loss) attributable to non-controlling interests	4.0	2.4	(1.0)
Comprehensive income (loss) attributable to Penske Automotive Group common stockholders	$ 1,179.6	$ 585.8	$ 467.5