Note 10 - Business Segments - Operating Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating income	$ 168,781	$ 149,389
JBI [Member] | Operating Segments [Member]
Operating income	114,200	95,300
DCS [Member] | Operating Segments [Member]
Operating income	40,600	44,800
ICS [Member] | Operating Segments [Member]
Operating income	8,900	4,400
JBT [Member] | Operating Segments [Member]
Operating income	$ 5,100	$ 4,900