Note 6 - Fair Value (Details) - Changes in Level 3 Assets Measured at Fair Value on a Recurring Basis (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total unrealized gains/(losses) included in other comprehensive income	$ 590	$ 588	$ (4,218)	$ 1,934
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of year			21,870	16,914
Balance at September 30 of each year	19,900	16,701	19,900	16,701
Total realized and unrealized gains/(losses) included in income			0	0
Total unrealized gains/(losses) included in other comprehensive income			0	0
Purchases of securities			5,885	11,682
Sales of securities			0	0
Calls and maturities			(7,925)	(12,255)
Net transfers into Level 3			$ 70	$ 360