Condensed Consolidating Financial Information - Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed consolidating balance sheet
Cash and cash equivalents	$ 24.0	$ 62.4	$ 36.3	$ 50.3
Accounts receivable, net	879.0	782.3
Inventories	3,408.2	3,463.5
Other current assets	102.0	85.6
Assets held for sale	8.3	12.7
Total current assets	4,421.5	4,406.5
Property and equipment, net	1,806.5	1,520.1
Intangible assets	1,711.4	1,731.2
Equity method investments	893.4	336.4
Other long-term assets	28.3	19.2
Total assets	8,861.1	8,013.4
Floor plan notes payable	2,084.5	2,247.2
Floor plan notes payable - non-trade	1,233.3	1,132.4
Accounts payable	497.4	493.8
Accrued expenses	360.0	378.1
Current portion of long-term debt	48.3	28.0
Liabilities held for sale	6.1	6.2
Total current liabilities	4,229.6	4,285.7
Long-term debt	1,828.8	1,247.0
Deferred tax liabilities	592.7	433.4
Other long-term liabilities	430.5	212.4
Total liabilities	7,081.6	6,178.5
Total equity	1,779.5	1,834.9	$ 1,681.2	1,522.1
Total liabilities and equity	$ 8,861.1	$ 8,013.4
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%	5.375%
Domestic Subsidiaries ownership guaranteeing obligations (as a percent)	100.00%
5.50% senior subordinated notes due 2026
Condensed consolidating balance sheet
Interest rate (as a percent)	5.50%
Domestic Subsidiaries ownership guaranteeing obligations (as a percent)	100.00%
Guarantor Subsidiaries
Condensed consolidating balance sheet
Domestic Subsidiaries ownership guaranteeing obligations (as a percent)	100.00%
Eliminations
Condensed consolidating balance sheet
Accounts receivable, net	$ (447.0)	$ (430.4)
Total current assets	(447.0)	(430.4)
Other long-term assets	(2,215.0)	(2,253.4)
Total assets	(2,662.0)	(2,683.8)
Accrued expenses	(447.0)	(430.4)
Total current liabilities	(447.0)	(430.4)
Long-term debt	(175.8)	(256.4)
Total liabilities	(622.8)	(686.8)
Total equity	(2,039.2)	(1,997.0)
Total liabilities and equity	(2,662.0)	(2,683.8)
Reportable legal entities | Penske Automotive Group
Condensed consolidating balance sheet
Accounts receivable, net	447.0	430.4
Other current assets	14.3	3.9
Total current assets	461.3	434.3
Property and equipment, net	3.3	4.0
Equity method investments	833.7	298.2
Other long-term assets	2,220.6	2,259.9
Total assets	3,518.9	2,996.4
Floor plan notes payable - non-trade	156.0	154.7
Accounts payable	4.9	4.8
Accrued expenses	0.9	0.1
Total current liabilities	161.8	159.6
Long-term debt	1,577.6	1,001.9
Total liabilities	1,739.4	1,161.5
Total equity	1,779.5	1,834.9
Total liabilities and equity	3,518.9	2,996.4
Reportable legal entities | Guarantor Subsidiaries
Condensed consolidating balance sheet
Cash and cash equivalents	9.4			13.1
Accounts receivable, net	483.6	400.8
Inventories	1,830.5	1,650.5
Other current assets	32.5	28.3
Assets held for sale	8.3	8.5
Total current assets	2,364.3	2,088.1
Property and equipment, net	961.0	822.0
Intangible assets	1,079.7	878.9
Other long-term assets	4.1	7.2
Total assets	4,409.1	3,796.2
Floor plan notes payable	1,178.0	1,295.0
Floor plan notes payable - non-trade	623.2	339.8
Accounts payable	171.9	143.3
Accrued expenses	77.2	112.3
Current portion of long-term debt	6.0	5.7
Liabilities held for sale	6.1	4.4
Total current liabilities	2,062.4	1,900.5
Long-term debt	186.0	109.2
Deferred tax liabilities	578.8	413.4
Other long-term liabilities	65.2	68.9
Total liabilities	2,892.4	2,492.0
Total equity	1,516.7	1,304.2
Total liabilities and equity	4,409.1	3,796.2
Reportable legal entities | Non-Guarantor Subsidiaries
Condensed consolidating balance sheet
Cash and cash equivalents	14.6	62.4	$ 36.3	$ 37.2
Accounts receivable, net	395.4	381.5
Inventories	1,577.7	1,813.0
Other current assets	55.2	53.4
Assets held for sale		4.2
Total current assets	2,042.9	2,314.5
Property and equipment, net	842.2	694.1
Intangible assets	631.7	852.3
Equity method investments	59.7	38.2
Other long-term assets	18.6	5.5
Total assets	3,595.1	3,904.6
Floor plan notes payable	906.5	952.2
Floor plan notes payable - non-trade	454.1	637.9
Accounts payable	320.6	345.7
Accrued expenses	728.9	696.1
Current portion of long-term debt	42.3	22.3
Liabilities held for sale		1.8
Total current liabilities	2,452.4	2,656.0
Long-term debt	241.0	392.3
Deferred tax liabilities	13.9	20.0
Other long-term liabilities	365.3	143.5
Total liabilities	3,072.6	3,211.8
Total equity	522.5	692.8
Total liabilities and equity	$ 3,595.1	$ 3,904.6