Condensed Consolidating Financial Information (Details 3) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed consolidating statement of cash flows
Net cash provided by (used in) continuing operating activities	$ 391.5	$ 359.3	$ 298.9
Investing activities:
Purchase of equipment and improvements	(199.5)	(176.1)	(175.0)
Acquisitions, net	(156.9)	(355.0)	(314.0)
Other	4.7	(22.6)	(2.6)
Net cash used in continuing investing activities	(351.7)	(553.7)	(491.6)
Financing activities:
Net (repayments) borrowings of long-term debt	(62.1)	(71.3)	81.1
Net borrowings (repayments) of floor plan notes payable - non-trade	154.2	26.1	191.1
Payment of deferred financing fees	(1.8)	(4.4)
Repurchases of common stock	(48.9)	(15.5)	(15.8)
Dividends	(84.8)	(70.5)	(56.0)
Other	(5.9)	0.3	0.2
Net cash (used in) provided by continuing financing activities	(49.3)	164.7	200.6
Net cash provided by (used in) discontinued operations	37.0	17.0	(1.5)
Effect of exchange rate changes on cash and cash equivalents	(1.4)	(1.3)
Net change in cash and cash equivalents	26.1	(14.0)	6.4
Cash and cash equivalents, beginning of period	36.3	50.3	43.9
Cash and cash equivalents, end of period	62.4	36.3	50.3
5.375% Senior Subordinated Notes Due 2024
Financing activities:
Issuance of senior subordinated notes		300.0
Reportable legal entities | Penske Automotive Group
Condensed consolidating statement of cash flows
Net cash provided by (used in) continuing operating activities	(4.9)	(70.7)	46.5
Investing activities:
Purchase of equipment and improvements	(1.3)	(1.7)	(1.3)
Other		4.2	(17.5)
Net cash used in continuing investing activities	(1.3)	2.5	(18.8)
Financing activities:
Net (repayments) borrowings of long-term debt	72.0	(100.0)	28.0
Net borrowings (repayments) of floor plan notes payable - non-trade	67.9	(41.4)	16.1
Payment of deferred financing fees		(4.4)
Repurchases of common stock	(48.9)	(15.5)	(15.8)
Dividends	(84.8)	(70.5)	(56.0)
Net cash (used in) provided by continuing financing activities	6.2	68.2	(27.7)
Reportable legal entities | Penske Automotive Group | 5.375% Senior Subordinated Notes Due 2024
Financing activities:
Issuance of senior subordinated notes		300.0
Reportable legal entities | Guarantor Subsidiaries
Condensed consolidating statement of cash flows
Net cash provided by (used in) continuing operating activities	230.3	209.7	18.4
Investing activities:
Purchase of equipment and improvements	(119.7)	(101.2)	(116.7)
Acquisitions, net	(93.2)	(175.3)	(103.4)
Other			10.7
Net cash used in continuing investing activities	(212.9)	(276.5)	(209.4)
Financing activities:
Net (repayments) borrowings of long-term debt	(4.9)	9.0	2.7
Net borrowings (repayments) of floor plan notes payable - non-trade	(58.3)	35.9	181.1
Distributions from (to) parent	8.8	5.5	0.9
Net cash (used in) provided by continuing financing activities	(54.4)	50.4	184.7
Net cash provided by (used in) discontinued operations	37.0	3.3	(15.4)
Net change in cash and cash equivalents		(13.1)	(21.7)
Cash and cash equivalents, beginning of period		13.1	34.8
Cash and cash equivalents, end of period			13.1
Reportable legal entities | Non-Guarantor Subsidiaries
Condensed consolidating statement of cash flows
Net cash provided by (used in) continuing operating activities	166.1	220.3	234.0
Investing activities:
Purchase of equipment and improvements	(78.5)	(73.2)	(57.0)
Acquisitions, net	(63.7)	(179.7)	(210.6)
Other	4.7	(26.8)	4.2
Net cash used in continuing investing activities	(137.5)	(279.7)	(263.4)
Financing activities:
Net (repayments) borrowings of long-term debt	(129.2)	19.7	50.4
Net borrowings (repayments) of floor plan notes payable - non-trade	144.6	31.6	(6.1)
Payment of deferred financing fees	(1.8)
Other	(5.9)	0.3	0.2
Distributions from (to) parent	(8.8)	(5.5)	(0.9)
Net cash (used in) provided by continuing financing activities	(1.1)	46.1	43.6
Net cash provided by (used in) discontinued operations		13.7	13.9
Effect of exchange rate changes on cash and cash equivalents	(1.4)	(1.3)
Net change in cash and cash equivalents	26.1	(0.9)	28.1
Cash and cash equivalents, beginning of period	36.3	37.2	9.1
Cash and cash equivalents, end of period	$ 62.4	$ 36.3	$ 37.2