Note 11 - Income Taxes (Details Textual) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
ISRAEL
National Corporate Tax Rate			16.00%
KENYA
National Corporate Tax Rate			37.50%
Domestic Tax Authority [Member]
Operating Loss Carryforwards					$ 261,000,000
State and Local Jurisdiction [Member]
Operating Loss Carryforwards					$ 191,000,000
General Business Tax Credit Carryforward [Member] | Minimum [Member]
Tax Credit Carryforward Expiration Year					2026
General Business Tax Credit Carryforward [Member] | Maximum [Member]
Tax Credit Carryforward Expiration Year					2036
General Business Tax Credit Carryforward [Member]
Tax Credit Carryforward Expiration Period					20 years
Effective Income Tax Rate Reconciliation, Percent			23.10%	29.70%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			35.00%
Effective Income Tax Rate Reconciliation, Tax Exempt Income, Amount	$ 1,130,000	$ 880,000	$ 2,330,000	$ 2,026,000
Deferred Tax Assets, Tax Credit Carryforwards, General Business					$ 70,800,000
Undistributed Earnings of Foreign Subsidiaries					$ 233,800,000