Note 13 - Segment Information - Operating Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating income	$ 145,814	$ 164,972	$ 163,615	$ 149,389	$ 194,361	$ 182,977	$ 175,792	$ 167,890	$ 623,789	$ 721,020	$ 715,694
JBI [Member] | Operating Segments [Member]
Operating income									407,000	450,000	477,000
DCS [Member] | Operating Segments [Member]
Operating income									171,000	205,000	163,000
ICS [Member] | Operating Segments [Member]
Operating income									23,000	36,000	36,000
JBT [Member] | Operating Segments [Member]
Operating income									$ 23,000	$ 30,000	$ 40,000