Note 10 - Business Segments - Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Assets	$ 4,421,657	$ 4,465,349
Operating Segments [Member] | JBI [Member]
Assets	2,094,000	2,108,000
Operating Segments [Member] | DCS [Member]
Assets	1,254,000	1,182,000
Operating Segments [Member] | ICS [Member]
Assets	197,000	204,000
Operating Segments [Member] | JBT [Member]
Assets	275,000	283,000
Corporate and Reconciling Items [Member]
Assets	$ 602,000	$ 688,000