(Goodwill acquired in business combination by reportable segment) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2016 USD ($)
Rollforward of goodwill by reportable segment
Goodwill balance as of December 31, 2015	$ 682,810	[1]
Adjustments to goodwill for purchase accounting	(797)
Goodwill balance as of June 30, 2016	682,013	[1]
TL
Rollforward of goodwill by reportable segment
Goodwill balance as of December 31, 2015	254,940
Adjustments to goodwill for purchase accounting	(797)
Goodwill balance as of June 30, 2016	254,143
LTL
Rollforward of goodwill by reportable segment
Goodwill balance as of December 31, 2015	197,312
Adjustments to goodwill for purchase accounting	0
Goodwill balance as of June 30, 2016	197,312
Global Solutions
Rollforward of goodwill by reportable segment
Goodwill balance as of December 31, 2015	230,558
Adjustments to goodwill for purchase accounting	0
Goodwill balance as of June 30, 2016	$ 230,558

[1] See Note 13 “Restatement of Previously Issued Financial Statements