(Intangible Assets Acquired from Business Acquisitions) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	$ 2,200	$ 2,100	$ 4,300	$ 4,100
Intangible assets
Gross Carrying Amount	97,253		97,253		$ 97,253
Accumulated Amortization	(25,846)		(25,846)		(21,559)
Net Carrying Value	71,407		71,407		75,694
TL
Intangible assets
Gross Carrying Amount	57,468		57,468		57,468
Accumulated Amortization	(12,122)		(12,122)		(9,714)
Net Carrying Value	45,346		45,346		47,754
LTL
Intangible assets
Gross Carrying Amount	1,358		1,358		1,358
Accumulated Amortization	(1,050)		(1,050)		(1,017)
Net Carrying Value	308		308		341
Global Solutions
Intangible assets
Gross Carrying Amount	38,427		38,427		38,427
Accumulated Amortization	(12,674)		(12,674)		(10,828)
Net Carrying Value	$ 25,753		$ 25,753		$ 27,599