Goodwill (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2015 USD ($) reporting_unit	Jun. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)
Carrying amount of goodwill attributable to each reportable business segment
Goodwill, gross	$ 421,481	$ 421,481	$ 422,250
Accumulated impairment losses	(29,221)	(29,221)	(29,221)
Goodwill	392,260	392,260	393,029
Foreign currency translation adjustments		(769)
Fleet Management Solutions [Member]
Carrying amount of goodwill attributable to each reportable business segment
Goodwill, gross	232,970	232,970	233,217
Accumulated impairment losses	(10,322)	(10,322)	(10,322)
Goodwill	222,648	222,648	222,895
Foreign currency translation adjustments		(247)
Dedicated Transportation Solutions [Member]
Carrying amount of goodwill attributable to each reportable business segment
Goodwill, gross	40,808	40,808	40,808
Accumulated impairment losses	0	0	0
Goodwill	40,808	40,808	40,808
Foreign currency translation adjustments		0
Supply Chain Solutions [Member]
Carrying amount of goodwill attributable to each reportable business segment
Goodwill, gross	147,703	147,703	148,225
Accumulated impairment losses	(18,899)	(18,899)	(18,899)
Goodwill	$ 128,804	128,804	$ 129,326
Foreign currency translation adjustments		$ (522)
Quantitative [Member]
Carrying amount of goodwill attributable to each reportable business segment
Number of reporting units | reporting_unit	4
Qualitative Test [Member]
Carrying amount of goodwill attributable to each reportable business segment
Number of reporting units | reporting_unit	1