Note 10 - Business Segments - Depreciation and Amortization (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Depreciation and amortization	$ 108,801	$ 95,959	$ 321,807	$ 281,198
Corporate and Reconciling Items [Member]
Depreciation and amortization	5,700	4,700	16,700	14,300
JBI [Member] | Operating Segments [Member]
Depreciation and amortization	43,100	40,400	128,100	121,200
DCS [Member] | Operating Segments [Member]
Depreciation and amortization	50,300	40,400	146,400	114,100
ICS [Member] | Operating Segments [Member]
Depreciation and amortization	400	300	1,100	900
JBT [Member] | Operating Segments [Member]
Depreciation and amortization	$ 9,300	$ 10,200	$ 29,500	$ 30,700