Note 10 - Business Segments - Depreciation and Amortization (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Depreciation and amortization	$ 139,371	$ 130,298	$ 276,916	$ 260,393
Segment Reconciling Items [Member]
Depreciation and amortization	14,000	10,800	27,400	21,500
JBI [Member] | Operating Segments [Member]
Depreciation and amortization	49,400	46,800	98,500	93,200
DCS [Member] | Operating Segments [Member]
Depreciation and amortization	58,400	55,600	115,300	111,900
ICS [Member] | Operating Segments [Member]
Depreciation and amortization	200	300	400	600
FMS [Member] | Operating Segments [Member]
Depreciation and amortization	8,600	8,200	17,600	16,400
JBT [Member] | Operating Segments [Member]
Depreciation and amortization	$ 8,800	$ 8,600	$ 17,700	$ 16,800