Note 10 - Business Segments - Operating Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Operating income	$ 175,503	$ 167,862	$ 505,427	$ 528,750
Segment Reconciling Items [Member]
Operating income	0	(100)	(100)	(100)
JBI [Member] | Operating Segments [Member]
Operating income	108,400	88,700	317,700	316,400
DCS [Member] | Operating Segments [Member]
Operating income	80,400	76,400	236,400	202,700
ICS [Member] | Operating Segments [Member]
Operating income	(18,300)	(5,600)	(50,300)	800
FMS [Member] | Operating Segments [Member]
Operating income	2,100	1,900	(6,500)	(13,700)
JBT [Member] | Operating Segments [Member]
Operating income	$ 2,900	$ 6,600	$ 8,200	$ 22,700