Commitments and Contingent Liabilities (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2012	Dec. 31, 2012
Commitments and Contingent Liabilities
Lease period, minimum	5 years
Lease period, maximum	20 years
Loss Contingencies
Letters of credit outstanding	18,997
Surety bonds posted	8,270
Holdings | Holdings Bond
Loss Contingencies
Senior unsecured notes issued		700,000
Senior subordinated convertible notes, interest rate		3.80%
Penske Truck Leasing Co., L.P.
Loss Contingencies
Limited partnership interest in Penske Truck Leasing Co (as a percent)	9.00%
Funds Used to Reduce Outstanding Debt		700,000
Penske Truck Leasing Co., L.P. | Holdings
Loss Contingencies
Subsidiary Contributed Capital		700,000
Subsidiary of limited liability company or limited partnership ownership interest given in exchange of amount received percentage		21.50%
Guarantee of Indebtedness of Others | GECC
Loss Contingencies
Annual fee pay for acting as co-obligor	950
Percentage of interest agreed to indemnify if GECC required to make any payments of principal or interest	9.00%
Value of interest payments included in maximum amount of Company's potential obligations	63,100