Note 2. Goodwill and Intangible Assets Goodwill rollforward (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014	Dec. 31, 2013
Goodwill [Line Items]
Goodwill, gross	$ 520,505	$ 520,628	$ 521,020
Accumulated impairment loss	(183,049)	(183,049)	(183,049)
Goodwill, net	337,456	337,579	337,971
Change in foreign currency exchange rates	(123)	(392)
Logistics [Member]
Goodwill [Line Items]
Goodwill, gross	55,180	55,303	55,695
Accumulated impairment loss	(48,236)	(48,236)	(48,236)
Goodwill, net	6,944	7,067	7,459
Change in foreign currency exchange rates	(123)	(392)
Truckload [Member]
Goodwill [Line Items]
Goodwill, gross	464,598	464,598	464,598
Accumulated impairment loss	(134,813)	(134,813)	(134,813)
Goodwill, net	329,785	329,785	329,785
Change in foreign currency exchange rates	0	0
Corporate and Eliminations [Member]
Goodwill [Line Items]
Goodwill, gross	727	727	727
Accumulated impairment loss	0	0	0
Goodwill, net	727	727	$ 727
Change in foreign currency exchange rates	$ 0	$ 0