Note 18 - Income Taxes - Foreign Subsidiaries Income Tax Years Open to Examination (Details)	12 Months Ended
	Dec. 31, 2017
ISRAEL | Earliest Tax Year [Member]
Countries	2015
ISRAEL | Latest Tax Year [Member]
Countries	2017
KENYA | Earliest Tax Year [Member]
Countries	2012
KENYA | Latest Tax Year [Member]
Countries	2017
GUATEMALA | Earliest Tax Year [Member]
Countries	2013
GUATEMALA | Latest Tax Year [Member]
Countries	2017
HONDURAS | Earliest Tax Year [Member]
Countries	2012
HONDURAS | Latest Tax Year [Member]
Countries	2017
GUADELOUPE | Earliest Tax Year [Member]
Countries	2015
GUADELOUPE | Latest Tax Year [Member]
Countries	2017
PHILIPPINES | Earliest Tax Year [Member]
Countries	2010
PHILIPPINES | Latest Tax Year [Member]
Countries	2017
NEW ZEALAND | Earliest Tax Year [Member]
Countries	2012
NEW ZEALAND | Latest Tax Year [Member]
Countries	2017