Note 4 - Investment Securities (Details) - Pooled Trust Preferred Securities (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2014
Note 4 - Investment Securities (Details) - Pooled Trust Preferred Securities [Line Items]
Book value	$ 393,840,000	$ 373,844,000
Investment securities available-for-sale	388,670,000	375,219,000
Total recognized OTTI credit loss	(43,000)
PreTSL IV [Member]
Note 4 - Investment Securities (Details) - Pooled Trust Preferred Securities [Line Items]
Class		Mezzanine*	[1]
Book value		243,000
Investment securities available-for-sale		208,000
Unrealized gains (losses)		(35,000)
Total recognized OTTI credit loss		(1,000)
Moody's/Fitch ratings		B1/B
Current number of performing banks		5
Actual deferrals and defaults as a % of total collateral		18.00%
Total performing collateral as a % of outstanding bonds		140.20%
PreTSL XVII [Member]
Note 4 - Investment Securities (Details) - Pooled Trust Preferred Securities [Line Items]
Class		Mezzanine
Book value		752,000
Investment securities available-for-sale		502,000
Unrealized gains (losses)		(250,000)
Total recognized OTTI credit loss		(222,000)
Moody's/Fitch ratings		C/C
Current number of performing banks		34
Current number of performing insurance companies		5
Actual deferrals and defaults as a % of total collateral		27.30%
Total performing collateral as a % of outstanding bonds		87.20%
PreTSL XIX [Member]
Note 4 - Investment Securities (Details) - Pooled Trust Preferred Securities [Line Items]
Class		Mezzanine
Book value		988,000
Investment securities available-for-sale		508,000
Unrealized gains (losses)		(480,000)
Total recognized OTTI credit loss		0
Moody's/Fitch ratings		C/C
Current number of performing banks		38
Current number of performing insurance companies		12
Actual deferrals and defaults as a % of total collateral		13.30%
Total performing collateral as a % of outstanding bonds		92.40%
PreTSL XXV [Member]
Note 4 - Investment Securities (Details) - Pooled Trust Preferred Securities [Line Items]
Class		Mezzanine
Book value		766,000
Investment securities available-for-sale		423,000
Unrealized gains (losses)		(343,000)
Total recognized OTTI credit loss		(222,000)
Moody's/Fitch ratings		C/C
Current number of performing banks		48
Current number of performing insurance companies		5
Actual deferrals and defaults as a % of total collateral		30.70%
Total performing collateral as a % of outstanding bonds		85.50%
PreTSL XXVI [Member]
Note 4 - Investment Securities (Details) - Pooled Trust Preferred Securities [Line Items]
Class		Mezzanine
Book value		469,000
Investment securities available-for-sale		337,000
Unrealized gains (losses)		(132,000)
Total recognized OTTI credit loss		(270,000)
Moody's/Fitch ratings		C/C
Current number of performing banks		43
Current number of performing insurance companies		7
Actual deferrals and defaults as a % of total collateral		25.90%
Total performing collateral as a % of outstanding bonds		91.00%
PreTSL XXVII [Member]
Note 4 - Investment Securities (Details) - Pooled Trust Preferred Securities [Line Items]
Class		Mezzanine
Book value		301,000
Investment securities available-for-sale		461,000
Unrealized gains (losses)		160,000
Total recognized OTTI credit loss		(438,000)
Moody's/Fitch ratings		C/C
Current number of performing banks		43
Current number of performing insurance companies		7
Actual deferrals and defaults as a % of total collateral		25.90%
Total performing collateral as a % of outstanding bonds		91.00%
Collateralized Debt Obligations [Member]
Note 4 - Investment Securities (Details) - Pooled Trust Preferred Securities [Line Items]
Book value	3,519,000	3,519,000
Investment securities available-for-sale	2,069,000	2,439,000
Unrealized gains (losses)		(1,080,000)
Total recognized OTTI credit loss		$ (1,153,000)

[1] Mezzanine* - only class of bonds still outstanding (represents the senior-most obligation of the trust)