Note 5 - Investment Securities (Details) - Credit-related Impairment Losses on Securities - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Credit-related Impairment Losses on Securities [Abstract]
Beginning Balance, January 1st			$ 3,966,000	$ 3,959,000
Additional credit-related impairment loss on securities for which an other-than-temporary impairment was previously recognized	$ 0	$ 0	3,000	7,000
Reductions for securities sold during the period			(3,039,000)
Ending Balance, September 30th	$ 930,000	$ 3,966,000	$ 930,000	$ 3,966,000