Condensed Consolidating Financial Information (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Condensed consolidating balance sheet
Cash and cash equivalents	$ 62.4	$ 36.3	$ 50.3	$ 43.9
Accounts receivable, net	782.3	707.1
Inventories	3,463.5	2,836.4
Other current assets	86.8	124.8
Assets held for sale	13.1	155.6
Total current assets	4,408.1	3,860.2
Property and equipment, net	1,520.1	1,331.6
Intangible assets	1,730.8	1,657.0
Equity method investments	336.4	352.8
Other long-term assets	27.3	26.6
Total assets	8,022.7	7,228.2
Floor plan notes payable	2,247.2	1,812.6
Floor plan notes payable - non-trade	1,132.4	933.8
Accounts payable	493.8	422.5
Accrued expenses	378.1	316.0
Current portion of long-term debt	29.2	37.2
Liabilities held for sale	6.2	108.2
Total current liabilities	4,286.9	3,630.3
Long-term debt	1,255.1	1,316.0
Deferred tax liabilities	433.4	409.9
Other long-term liabilities	212.4	190.8
Total liabilities	6,187.8	5,547.0
Total equity	1,834.9	1,681.2	$ 1,522.1	1,316.3
Total liabilities and equity	$ 8,022.7	$ 7,228.2
5.75% Senior Subordinated Notes Due 2022
Condensed consolidating balance sheet
Interest rate (as a percent)	5.75%	5.75%
Domestic Subsidiaries ownership guaranteeing obligations (as a percent)	100.00%
5.375% Senior Subordinated Notes Due 2024
Condensed consolidating balance sheet
Interest rate (as a percent)	5.375%	5.375%
Domestic Subsidiaries ownership guaranteeing obligations (as a percent)	100.00%
Penske Automotive Group | 5.75% Senior Subordinated Notes Due 2022
Condensed consolidating balance sheet
Interest rate (as a percent)	5.75%	5.75%	5.75%
Penske Automotive Group | 5.375% Senior Subordinated Notes Due 2024
Condensed consolidating balance sheet
Interest rate (as a percent)	5.375%	5.375%
Guarantor Subsidiaries
Condensed consolidating balance sheet
Domestic Subsidiaries ownership guaranteeing obligations (as a percent)	100.00%
Eliminations
Condensed consolidating balance sheet
Accounts receivable, net	$ (430.4)	$ (409.6)
Total current assets	(430.4)	(409.6)
Other long-term assets	(2,253.4)	(1,990.8)
Total assets	(2,683.8)	(2,400.4)
Accrued expenses	(430.4)	(409.6)
Total current liabilities	(430.4)	(409.6)
Long-term debt	(256.4)	(247.0)
Total liabilities	(686.8)	(656.6)
Total equity	(1,997.0)	(1,743.8)
Total liabilities and equity	(2,683.8)	(2,400.4)
Reportable legal entities | Penske Automotive Group
Condensed consolidating balance sheet
Accounts receivable, net	430.4	409.6
Other current assets	3.9	4.5
Total current assets	434.3	414.1
Property and equipment, net	4.0	4.3
Equity method investments	298.2	285.5
Other long-term assets	2,268.0	2,005.0
Total assets	3,004.5	2,708.9
Floor plan notes payable - non-trade	154.7	86.8
Accounts payable	4.8	2.9
Accrued expenses	0.1
Total current liabilities	159.6	89.7
Long-term debt	1,010.0	938.0
Total liabilities	1,169.6	1,027.7
Total equity	1,834.9	1,681.2
Total liabilities and equity	3,004.5	2,708.9
Reportable legal entities | Guarantor Subsidiaries
Condensed consolidating balance sheet
Cash and cash equivalents			$ 13.1	34.8
Accounts receivable, net	400.8	392.6
Inventories	1,650.5	1,481.5
Other current assets	29.5	58.3
Assets held for sale	8.9	150.9
Total current assets	2,089.7	2,083.3
Property and equipment, net	822.0	754.6
Intangible assets	878.5	817.9
Other long-term assets	7.2	4.4
Total assets	3,797.4	3,660.2
Floor plan notes payable	1,295.0	1,102.0
Floor plan notes payable - non-trade	339.8	398.1
Accounts payable	143.3	208.3
Accrued expenses	112.3	123.3
Current portion of long-term debt	6.9	4.6
Liabilities held for sale	4.4	105.9
Total current liabilities	1,901.7	1,942.2
Long-term debt	109.2	116.1
Deferred tax liabilities	413.4	385.6
Other long-term liabilities	68.9	66.9
Total liabilities	2,493.2	2,510.8
Total equity	1,304.2	1,149.4
Total liabilities and equity	3,797.4	3,660.2
Reportable legal entities | Non-Guarantor Subsidiaries
Condensed consolidating balance sheet
Cash and cash equivalents	62.4	36.3	$ 37.2	$ 9.1
Accounts receivable, net	381.5	314.5
Inventories	1,813.0	1,354.9
Other current assets	53.4	62.0
Assets held for sale	4.2	4.7
Total current assets	2,314.5	1,772.4
Property and equipment, net	694.1	572.7
Intangible assets	852.3	839.1
Equity method investments	38.2	67.3
Other long-term assets	5.5	8.0
Total assets	3,904.6	3,259.5
Floor plan notes payable	952.2	710.6
Floor plan notes payable - non-trade	637.9	448.9
Accounts payable	345.7	211.3
Accrued expenses	696.1	602.3
Current portion of long-term debt	22.3	32.6
Liabilities held for sale	1.8	2.3
Total current liabilities	2,656.0	2,008.0
Long-term debt	392.3	508.9
Deferred tax liabilities	20.0	24.3
Other long-term liabilities	143.5	123.9
Total liabilities	3,211.8	2,665.1
Total equity	692.8	594.4
Total liabilities and equity	$ 3,904.6	$ 3,259.5