Revenue Earning Equipment Level 3 Fair Value Measurement (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenue Earning Equipment [Line Items]
Total losses	$ 9,213	$ 11,665	$ 46,430	$ 31,504
Net book value of assets held for sale not exceeding fair value	77,000	76,000	77,000	76,000
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Nonrecurring
Revenue Earning Equipment [Line Items]
Assets held for sale	31,808	81,134	31,808	81,134
Total losses	9,213	11,665	46,430	31,504
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Nonrecurring | Trucks
Revenue Earning Equipment [Line Items]
Assets held for sale	14,081	17,091	14,081	17,091
Total losses	6,215	2,528	22,942	6,842
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Nonrecurring | Tractors
Revenue Earning Equipment [Line Items]
Assets held for sale	15,448	61,480	15,448	61,480
Total losses	1,127	7,985	18,444	22,073
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Nonrecurring | Trailers
Revenue Earning Equipment [Line Items]
Assets held for sale	2,279	2,563	2,279	2,563
Total losses	$ 1,871	$ 1,152	$ 5,044	$ 2,589