Note 7 - Fair Value of Financial Instruments (Details) - Asstets Measured on a Recurring Basis Using Significant Unobservable Inputs - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Impairment charges on Level 3	$ 0	$ 0	$ (13)	$ 21
Fair Value, Inputs, Level 3 [Member] | Collateralized Debt Obligations [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance,	2,006	2,977	3,193	2,850
Balance,	1,670	3,179	1,670	3,179
Unrealized gains (losses)	220	212	669	346
Paydowns	0	(10)	(19)	(10)
Proceeds from sales	(414)	0	(1,952)	0
Realized losses	(142)	0	(218)	0
Impairment charges on Level 3	0	0	(3)	(7)
Fair Value, Inputs, Level 3 [Member] | Corporate Debt Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance,	2,684	3,006	3,005	3,006
Balance,	2,701	3,006	2,701	3,006
Unrealized gains (losses)	17	0	(304)	0
Paydowns	0	0	0	0
Proceeds from sales	0	0	0	0
Realized losses	0	0	0	0
Impairment charges on Level 3	$ 0	$ 0	$ 0	$ 0