Note 8 - Comprehensive Income (Loss) (Details) - Reclassification Out of Accumulated Other Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012
Unrealized gains and losses on available-for-sale securities:
Total before tax									$ 22,212		$ 9,671	$ 3,595
Tax expense	1,308	3,355	3,160	898	776	1,575	1,733	(328)	8,721		3,756	1,416
Total after tax									13,491		5,915	2,179
Reclassification out of Accumulated Other Comprehensive Income [Member]
Unrealized gains and losses on available-for-sale securities:
Realized gain on sale of securities									1,015
Impairment expense									(1)	[1]
Total before tax									1,014	[1]
Tax expense									(385)	[1]
Total after tax									$ 629	[1]

[1] Amounts in parentheses indicate debits to profit/loss