Note 15 - Fair Value Measurements and Fair Values of Financial Instruments (Details) - Assets Measured on a Recurring Basis Using Significant Unobservable Inputs - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Impairment charges on Level 3	$ (13)	$ 21	$ 0
Fair Value, Inputs, Level 3 [Member] | Collateralized Debt Obligations [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, January 1,	3,193	2,850	3,187
Balance, December 31,	1,883	3,193	2,850
Unrealized gains (losses)	882	360	171
Paydowns	(19)	(10)	(508)
Proceeds from sales	(1,952)
Realized losses	(218)
Impairment charges on Level 3	(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, January 1,	3,005	3,006	3,007
Balance, December 31,	2,834	3,005	3,006
Unrealized gains (losses)	$ (171)	$ (1)	(1)
Paydowns			0
Proceeds from sales			0
Realized losses			0
Impairment charges on Level 3			$ 0