Note 10 - Business Segments - Operating Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Operating income	$ 214,812	$ 163,615	$ 383,594	$ 313,004
Corporate and Reconciling Items [Member]
Operating income	(100)
JBI [Member] | Operating Segments [Member]
Operating income	134,000	109,700	248,200	205,000
DCS [Member] | Operating Segments [Member]
Operating income	58,500	48,600	99,000	93,300
ICS [Member] | Operating Segments [Member]
Operating income	14,900	(200)	23,800	4,200
JBT [Member] | Operating Segments [Member]
Operating income	$ 7,500	$ 5,500	$ 12,600	$ 10,500