Note 4 - Non-operating Income - Schedule of Non-operating Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Equity in earnings of unconsolidated investments	$ 1,806	$ 1,538	$ 4,926	$ 3,924
Dividends and other net realized gains and losses on sales of securities	1,892	1,588	5,654	5,093
Interest income	1,393	1,424	4,209	3,885
Other non-operating income	$ 5,091	$ 4,550	$ 14,789	$ 12,902