Note 4 - Non-operating Income Component (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Equity in earnings of unconsolidated investments	$ 1,615	$ 1,268	$ 3,120	$ 2,386
Dividends and other net realized gains and losses on sales of securities	1,901	1,629	3,762	3,505
Interest income	1,409	1,233	2,816	2,461
Other non-operating income	$ 4,925	$ 4,130	$ 9,698	$ 8,352