Condensed Consolidating Financial Information - Balance Sheet (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2015
Condensed consolidating balance sheet
Cash and cash equivalents	$ 72.2	$ 24.0	$ 45.6	$ 62.4
Accounts receivable, net	852.2	879.0
Inventories	3,565.8	3,408.2
Other current assets	99.3	73.9
Assets held for sale		8.4
Total current assets	4,589.5	4,393.5
Property and equipment, net	1,874.7	1,806.5
Intangible assets	1,985.4	1,711.3
Equity method investments	906.8	893.4
Other long-term assets	39.0	28.3
Total assets	9,395.4	8,833.0
Floor plan notes payable	2,104.8	2,084.5
Floor plan notes payable - non-trade	1,296.4	1,233.3
Accounts payable	555.9	497.4
Accrued expenses	413.9	360.0
Current portion of long-term debt	48.4	48.3
Liabilities held for sale	0.8	6.1
Total current liabilities	4,420.2	4,229.6
Long-term debt	1,989.0	1,828.8
Deferred tax liabilities	608.6	564.6
Other long-term liabilities	480.7	430.5
Total liabilities	7,498.5	7,053.5
Total equity	1,896.9	1,779.5
Total liabilities and equity	$ 9,395.4	$ 8,833.0
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%
5.50% senior subordinated notes due 2026
Condensed consolidating balance sheet
Interest rate (as a percent)	5.50%	5.50%
Domestic Subsidiaries ownership guaranteeing obligations (as a percent)	100.00%
Penske Automotive Group
Condensed consolidating balance sheet
Accounts receivable, net	$ 434.1	$ 447.0
Other current assets	14.9	14.3
Total current assets	449.0	461.3
Property and equipment, net	3.7	3.3
Equity method investments	847.2	833.7
Other long-term assets	2,384.7	2,220.6
Total assets	3,684.6	3,518.9
Floor plan notes payable - non-trade	154.9	156.0
Accounts payable	6.7	4.9
Accrued expenses	1.0	0.9
Total current liabilities	162.6	161.8
Long-term debt	1,625.1	1,577.6
Total liabilities	1,787.7	1,739.4
Total equity	1,896.9	1,779.5
Total liabilities and equity	3,684.6	3,518.9
Guarantor Subsidiaries
Condensed consolidating balance sheet
Cash and cash equivalents	1.5	9.4
Accounts receivable, net	371.2	483.6
Inventories	1,896.2	1,830.5
Other current assets	16.1	14.6
Assets held for sale		8.4
Total current assets	2,285.0	2,346.5
Property and equipment, net	967.7	961.0
Intangible assets	1,236.3	1,079.6
Other long-term assets	14.8	4.1
Total assets	4,503.8	4,391.2
Floor plan notes payable	1,123.1	1,178.0
Floor plan notes payable - non-trade	659.7	623.2
Accounts payable	147.5	171.9
Accrued expenses	93.8	77.2
Current portion of long-term debt	6.5	6.0
Liabilities held for sale	0.8	6.1
Total current liabilities	2,031.4	2,062.4
Long-term debt	198.3	186.0
Deferred tax liabilities	602.9	560.9
Other long-term liabilities	68.2	65.2
Total liabilities	2,900.8	2,874.5
Total equity	1,603.0	1,516.7
Total liabilities and equity	4,503.8	4,391.2
Non-Guarantor Subsidiaries
Condensed consolidating balance sheet
Cash and cash equivalents	70.7	14.6	$ 45.6	$ 62.4
Accounts receivable, net	481.0	395.4
Inventories	1,669.6	1,577.7
Other current assets	68.3	45.0
Total current assets	2,289.6	2,032.7
Property and equipment, net	903.3	842.2
Intangible assets	749.1	631.7
Equity method investments	59.6	59.7
Other long-term assets	18.8	18.6
Total assets	4,020.4	3,584.9
Floor plan notes payable	981.7	906.5
Floor plan notes payable - non-trade	481.8	454.1
Accounts payable	401.7	320.6
Accrued expenses	753.2	728.9
Current portion of long-term debt	41.9	42.3
Total current liabilities	2,660.3	2,452.4
Long-term debt	345.9	241.0
Deferred tax liabilities	5.7	3.7
Other long-term liabilities	412.5	365.3
Total liabilities	3,424.4	3,062.4
Total equity	596.0	522.5
Total liabilities and equity	4,020.4	3,584.9
Eliminations
Condensed consolidating balance sheet
Accounts receivable, net	(434.1)	(447.0)
Total current assets	(434.1)	(447.0)
Other long-term assets	(2,379.3)	(2,215.0)
Total assets	(2,813.4)	(2,662.0)
Accrued expenses	(434.1)	(447.0)
Total current liabilities	(434.1)	(447.0)
Long-term debt	(180.3)	(175.8)
Total liabilities	(614.4)	(622.8)
Total equity	(2,199.0)	(2,039.2)
Total liabilities and equity	$ (2,813.4)	$ (2,662.0)