Note 6 - Restructuring and Cost Savings Initiatives - Summary of Asset Groups Impaired (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Impairment of long lived property, equipment, and right-of-use assets	$ 0	$ 0	$ 26,569	$ 0
Revenue Equipment [Member] | Highway Services and Dedicated [Member]
Impairment of long lived property, equipment, and right-of-use assets	0		16,779
Terminal Property [Member] | Highway Services and Dedicated [Member]
Impairment of long lived property, equipment, and right-of-use assets	0		7,319
Leased Office Facility [Member]
Impairment of long lived property, equipment, and right-of-use assets	0		2,200
Leased Office Facility [Member] | Managed Freight [Member]
Impairment of long lived property, equipment, and right-of-use assets	0		2,236
Training and Orientation Center [Member] | Highway Services [Member]
Impairment of long lived property, equipment, and right-of-use assets	$ 0		$ 235