Fair Value Measurements (Details 1) (USD $) | Sep. 30, 2013 | Dec. 31, 2012 | Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2012 |
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Measurements, Nonrecurring [Member] |
| | | | Revenue earning equipment, Trucks [Member] | Revenue earning equipment, Trucks [Member] | Revenue earning equipment, Trucks [Member] | Revenue earning equipment, Trucks [Member] | Revenue earning equipment, Tractors [Member] | Revenue earning equipment, Tractors [Member] | Revenue earning equipment, Tractors [Member] | Revenue earning equipment, Tractors [Member] | Revenue earning equipment, Trailers [Member] | Revenue earning equipment, Trailers [Member] | Revenue earning equipment, Trailers [Member] | Revenue earning equipment, Trailers [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Inputs, Level 3 [Member] |
| | | | | | | | | | | | | | | | | | Revenue earning equipment, Trucks [Member] | Revenue earning equipment, Trucks [Member] | Revenue earning equipment, Tractors [Member] | Revenue earning equipment, Tractors [Member] | Revenue earning equipment, Trailers [Member] | Revenue earning equipment, Trailers [Member] | | | Revenue earning equipment, Trucks [Member] | Revenue earning equipment, Trucks [Member] | Revenue earning equipment, Tractors [Member] | Revenue earning equipment, Tractors [Member] | Revenue earning equipment, Trailers [Member] | Revenue earning equipment, Trailers [Member] | | | Revenue earning equipment, Trucks [Member] | Revenue earning equipment, Trucks [Member] | Revenue earning equipment, Tractors [Member] | Revenue earning equipment, Tractors [Member] | Revenue earning equipment, Trailers [Member] | Revenue earning equipment, Trailers [Member] |
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Assets held for sale at fair value | | | | | | | | | | | | | | | | | | | $0 | $0 | $0 | $0 | $0 | $0 | $0 | $0 | $0 | $0 | $0 | $0 | $0 | $0 | $0 | $0 | $26,549,000 | $21,017,000 | $10,546,000 | $11,994,000 | $15,332,000 | $8,616,000 | $671,000 | $407,000 |
Total Losses | | | 3,994,000 | 5,161,000 | 12,945,000 | 12,975,000 | 2,042,000 | 3,664,000 | 7,518,000 | 9,153,000 | 1,677,000 | 1,097,000 | 4,185,000 | 2,639,000 | 275,000 | 400,000 | 1,242,000 | 1,183,000 | | | | | | | | | | | | | | | | | | | | | | | | |
Fair Value Measurements (Textuals) (Abstract) | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Fair value of total debt | $4,140,000,000 | $3,990,000,000 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |