Related Party Transactions (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Related party transactions
Provider's cost reimbursed	$ 200	$ 385	$ 436
Automotive Group Realty, LLC
Related party transactions
Amount paid under non-cancelable lease agreements	200	385	436
Penske Corporation and its affiliates
Related party transactions
Provider's cost reimbursed	5,294	4,913	5,421
Amount of Provider's cost received	31	72	41
Amount due from related party	2	2
Amount due to related party	486	546
Penske Truck Leasing Corporation and other subsidiaries
Related party transactions
General partner ownership percentage	41.10%
Penske Truck Leasing Corporation and other subsidiaries | General Electric Capital Corporation
Related party transactions
General partner ownership percentage	49.90%
PTL
Related party transactions
Limited partnership interest in Penske Truck Leasing Co (as a percent)	9.00%
Pro rata cash dividends received	18,531	7,751	8,804
PTL | New Jersey
Related party transactions
Income per year from sublease of a portion of dealership	60
Amount paid for roadside assistance and other services			592
Expenses due to third party vendors			309
Disaster recovery site, annual fees paid	$ 70