(Goodwill acquired in business combination by reportable segment) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2019
Rollforward of goodwill by reportable segment
Accumulated goodwill impairment, beginning balance			$ 376,483,000
Goodwill, beginning balance			264,826,000
Goodwill impairment charges	$ (92,900,000)		(127,454,000)
Goodwill, ending balance	137,372,000		137,372,000
Accumulated goodwill impairment, ending balance	503,937,000		503,937,000
Ascent
Rollforward of goodwill by reportable segment
Accumulated goodwill impairment, beginning balance			46,763,000
Goodwill, beginning balance			171,900,000
Goodwill impairment charges	(34,500,000)		(34,528,000)
Goodwill, ending balance	137,372,000		137,372,000
Accumulated goodwill impairment, ending balance	81,291,000		81,291,000
Active On-Demand
Rollforward of goodwill by reportable segment
Accumulated goodwill impairment, beginning balance			0
Goodwill, beginning balance			0
Goodwill impairment charges			0
Goodwill, ending balance	0		0
Accumulated goodwill impairment, ending balance	0		0
LTL [Member]
Rollforward of goodwill by reportable segment
Accumulated goodwill impairment, beginning balance			197,312,000
Goodwill, beginning balance			0
Goodwill impairment charges			0
Goodwill, ending balance	0		0
Accumulated goodwill impairment, ending balance	197,312,000		197,312,000
TL
Rollforward of goodwill by reportable segment
Accumulated goodwill impairment, beginning balance			132,408,000
Goodwill, beginning balance			92,926,000
Goodwill impairment charges		$ (92,900,000)	(92,926,000)
Goodwill, ending balance	0		0
Accumulated goodwill impairment, ending balance	$ 225,334,000		$ 225,334,000