Note 10 - Business Segments - Operating Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Operating income	$ 241,546	$ 175,183	$ 449,198	$ 329,924
Segment Reconciling Items [Member]
Operating income	(100)	(100)	(200)	(100)
JBI [Member] | Operating Segments [Member]
Operating income	134,600	107,000	242,100	209,200
DCS [Member] | Operating Segments [Member]
Operating income	79,000	83,100	153,300	156,000
ICS [Member] | Operating Segments [Member]
Operating income	3,100	(13,100)	10,400	(32,000)
FMS [Member] | Operating Segments [Member]
Operating income	10,700	(5,200)	19,200	(8,500)
JBT [Member] | Operating Segments [Member]
Operating income	$ 14,200	$ 3,500	$ 24,400	$ 5,300