Note 14 - Segment Information - Operating Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating income	$ 205,074	$ 167,862	$ 193,093	$ 167,795	$ 122,740	$ 174,688	$ 214,812	$ 168,781	$ 733,825	$ 681,021	$ 623,789
JBI [Member] | Operating Segments [Member]
Operating income									447,000	401,000	407,000
DCS [Member] | Operating Segments [Member]
Operating income									269,000	193,000	171,000
ICS [Member] | Operating Segments [Member]
Operating income									(11,000)	50,000	23,000
JBT [Member] | Operating Segments [Member]
Operating income									$ 29,000	$ 37,000	$ 23,000