Note 19 - Business Segments - Long Lived Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Long Lived Assets, Geographic Area	$ 2,221,267	$ 2,133,289	$ 1,941,239
UNITED STATES
Long Lived Assets, Geographic Area	1,696,439	1,510,986	1,414,523
KENYA
Long Lived Assets, Geographic Area	301,956	340,970	327,157
Other Foreign Countries [Member]
Long Lived Assets, Geographic Area	$ 222,872	$ 281,333	$ 199,559