Fair Value Measurements (Details) (USD $)			3 Months Ended				9 Months Ended				3 Months Ended				9 Months Ended				3 Months Ended				9 Months Ended				3 Months Ended				9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014 Fair Value, Measurements, Nonrecurring [Member]		Sep. 30, 2013 Fair Value, Measurements, Nonrecurring [Member]		Sep. 30, 2014 Fair Value, Measurements, Nonrecurring [Member]		Sep. 30, 2013 Fair Value, Measurements, Nonrecurring [Member]		Sep. 30, 2014 Fair Value, Measurements, Nonrecurring [Member] Revenue earning equipment, Trucks [Member]		Sep. 30, 2013 Fair Value, Measurements, Nonrecurring [Member] Revenue earning equipment, Trucks [Member]		Sep. 30, 2014 Fair Value, Measurements, Nonrecurring [Member] Revenue earning equipment, Trucks [Member]		Sep. 30, 2013 Fair Value, Measurements, Nonrecurring [Member] Revenue earning equipment, Trucks [Member]		Sep. 30, 2014 Fair Value, Measurements, Nonrecurring [Member] Revenue earning equipment, Tractors [Member]		Sep. 30, 2013 Fair Value, Measurements, Nonrecurring [Member] Revenue earning equipment, Tractors [Member]		Sep. 30, 2014 Fair Value, Measurements, Nonrecurring [Member] Revenue earning equipment, Tractors [Member]		Sep. 30, 2013 Fair Value, Measurements, Nonrecurring [Member] Revenue earning equipment, Tractors [Member]		Sep. 30, 2014 Fair Value, Measurements, Nonrecurring [Member] Revenue earning equipment, Trailers [Member]		Sep. 30, 2013 Fair Value, Measurements, Nonrecurring [Member] Revenue earning equipment, Trailers [Member]		Sep. 30, 2014 Fair Value, Measurements, Nonrecurring [Member] Revenue earning equipment, Trailers [Member]		Sep. 30, 2013 Fair Value, Measurements, Nonrecurring [Member] Revenue earning equipment, Trailers [Member]		Sep. 30, 2014 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 3 [Member]		Sep. 30, 2013 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 3 [Member]		Sep. 30, 2014 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 3 [Member] Revenue earning equipment, Trucks [Member]		Sep. 30, 2013 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 3 [Member] Revenue earning equipment, Trucks [Member]		Sep. 30, 2014 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 3 [Member] Revenue earning equipment, Tractors [Member]		Sep. 30, 2013 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 3 [Member] Revenue earning equipment, Tractors [Member]		Sep. 30, 2014 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 3 [Member] Revenue earning equipment, Trailers [Member]		Sep. 30, 2013 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 3 [Member] Revenue earning equipment, Trailers [Member]
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis
Assets held for sale at fair value																																			$ 13,785,000	[1]	$ 26,549,000	[1]	$ 8,437,000	[1]	$ 10,546,000	[1]	$ 4,666,000	[1]	$ 15,332,000	[1]	$ 682,000	[1]	$ 671,000	[1]
Total Losses			2,377,000	[1],[2]	3,994,000	[1],[2]	8,567,000	[1],[2]	12,945,000	[1],[2]	1,527,000	[1],[2]	2,042,000	[1],[2]	4,981,000	[1],[2]	7,518,000	[1],[2]	530,000	[1],[2]	1,677,000	[1],[2]	2,824,000	[1],[2]	4,185,000	[1],[2]	320,000	[1],[2]	275,000	[1],[2]	762,000	[1],[2]	1,242,000	[1],[2]
Fair Value Measurements (Textuals) (Abstract)
Fair value of total debt	$ 4,600,000,000	$ 4,280,000,000

[1] Represents the portion of all revenue earning equipment held for sale that is recorded at fair value, less costs to sell.

[2] Total losses represent fair value adjustments for all vehicles held for sale throughout the period for which fair value was less than carrying value.