Commitments and Contingent Liabilities (Details) (USD $)	12 Months Ended			9 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Holdings Holdings Bond	Dec. 31, 2012 Penske Truck Leasing Co., L.P.	Dec. 31, 2012 Penske Truck Leasing Co., L.P. Holdings	Dec. 31, 2012 Guarantee of Indebtedness of Others GECC
Commitments and Contingent Liabilities
Lease period, minimum	5 years
Lease period, maximum	20 years
Total rent obligations under leases	$ 4,800,000,000
Minimum future rental payments required under operating leases
2013	180,553,000
2014	178,187,000
2015	177,785,000
2016	177,346,000
2017	176,696,000
2018 and thereafter	3,941,993,000
Total	4,832,560,000
Rent expense	173,280,000	165,346,000	157,768,000
Total rental payments to related parties	200,000	385,000	436,000
Aggregate rent paid by the tenants	11,545,000
Aggregate rent currently guaranteed by the Company	194,637,000
Loss Contingencies
Limited partnership interest in Penske Truck Leasing Co (as a percent)					9.00%
Senior unsecured notes issued				700,000,000
Senior subordinated convertible notes, interest rate (as a percent)				3.80%
Subsidiary Contributed Capital						700,000,000
Subsidiary of limited liability company or limited partnership ownership interest given in exchange of amount received percentage						21.50%
Funds Used to Reduce Outstanding Debt					700,000,000
Percentage of interest agreed to indemnify if GECC required to make any payments of principal or interest							9.00%
Annual fee pay for acting as co-obligor							950,000
Value of interest payments included in maximum amount of Company's potential obligations							63,100,000
Letters of credit outstanding	500,000
Surety bonds posted	$ 8,154,000