Legal and Regulatory Matters - Additional Information (Details) - Pacer International $ in Millions			1 Months Ended	12 Months Ended
	Jul. 17, 2015 USD ($) claimant	Mar. 06, 2015 class_action claimant	Jun. 30, 2015 USD ($) claimant	Dec. 31, 2016 operator	Dec. 31, 2014 claimant	Dec. 31, 2012 operator
Loss Contingencies [Line Items]
Number of owner operators (in operators) | operator				150		150
Number of claims heard by court (in claimants) | claimant	7	200	5		7
Amount claimed | $	$ 2.9		$ 0.9
Number of class actions related to remaining claimants (in class actions) | class_action		3