Commitments and Contingent Liabilities (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015
Commitments and Contingent Liabilities
Lease period, minimum		5 years
Lease period, maximum		20 years
Loss Contingencies
Letters of credit outstanding		$ 30,500
Surety bonds posted		13,200
Holdings | Holdings Bond
Loss Contingencies
Senior unsecured notes issued		$ 700,000
Senior subordinated convertible notes, interest rate (as a percent)		3.80%
Penske Truck Leasing Co., L.P.
Loss Contingencies
Ownership interest in Penske Truck Leasing Co (as a percent)		9.00%	9.00%
GECC
Loss Contingencies
Ownership interest in Penske Truck Leasing Co (as a percent)		29.90%	29.90%
Mitsui and Co
Loss Contingencies
Ownership interest in Penske Truck Leasing Co (as a percent)		20.00%	20.00%
Purchase of ownership interest	20.00%
Penske Corporation
Loss Contingencies
Ownership interest in Penske Truck Leasing Co (as a percent)		41.10%	41.10%
Guarantee of Indebtedness of Others | GECC
Loss Contingencies
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
Value of principal repayment included in maximum amount of Company's potential obligations		$ 63,100