Note 13 - Segment Information - Operating Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating income	$ 122,740	$ 174,688	$ 214,812	$ 168,781	$ 145,814	$ 164,972	$ 163,615	$ 149,389	$ 681,021	$ 623,789	$ 721,020
JBI [Member] \| Operating Segments [Member]
Operating income									401,000	407,000	450,000
DCS [Member] \| Operating Segments [Member]
Operating income									193,000	171,000	205,000
ICS [Member] \| Operating Segments [Member]
Operating income									50,000	23,000	36,000
JBT [Member] \| Operating Segments [Member]
Operating income									$ 37,000	$ 23,000	$ 30,000