Note 4 - Fair Value Measurements - Assets Measured at Fair Value on Nonrecurring Basis (Details) - USD ($)		3 Months Ended	9 Months Ended	12 Months Ended
		Sep. 30, 2016	Sep. 30, 2016	Dec. 31, 2015
Loans Held for Sale [Member] | Fair Value, Inputs, Level 1 [Member]
Asset fair value		$ 0	$ 0	$ 0
Loans Held for Sale [Member] | Fair Value, Inputs, Level 2 [Member]
Asset fair value		5,879,000	5,879,000	3,779,000
Loans Held for Sale [Member] | Fair Value, Inputs, Level 3 [Member]
Asset fair value		0	0	0
Loans Held for Sale [Member]
Asset fair value		5,879,000	5,879,000	3,779,000
Fair value gain (loss)		24,000	72,000	3,000
Mortgage Servicing Rights [Member] | Fair Value, Inputs, Level 1 [Member]
Asset fair value		0	0	0
Mortgage Servicing Rights [Member] | Fair Value, Inputs, Level 2 [Member]
Asset fair value		1,537,000	1,537,000	1,499,000
Mortgage Servicing Rights [Member] | Fair Value, Inputs, Level 3 [Member]
Asset fair value		0	0	0
Mortgage Servicing Rights [Member]
Asset fair value		1,537,000	1,537,000	1,499,000
Fair value gain (loss)		0	0	0
Loans Receivable [Member] | Fair Value, Inputs, Level 1 [Member]
Asset fair value	[1]	0	0	0
Loans Receivable [Member] | Fair Value, Inputs, Level 2 [Member]
Asset fair value	[1]	5,091,000	5,091,000	4,790,000
Loans Receivable [Member] | Fair Value, Inputs, Level 3 [Member]
Asset fair value	[1]	0	0	0
Loans Receivable [Member]
Asset fair value	[1]	5,091,000	5,091,000	4,790,000
Fair value gain (loss)	[1]	(371,000)	(553,000)	(373,000)
Real Estate Net [Member] | Fair Value, Inputs, Level 1 [Member]
Asset fair value	[2]	0	0	0
Real Estate Net [Member] | Fair Value, Inputs, Level 2 [Member]
Asset fair value	[2]	815,000	815,000	2,045,000
Real Estate Net [Member] | Fair Value, Inputs, Level 3 [Member]
Asset fair value	[2]	0	0	0
Real Estate Net [Member]
Asset fair value	[2]	815,000	815,000	2,045,000
Fair value gain (loss)	[2]	0	(241,000)	(262,000)
Fair Value, Inputs, Level 1 [Member]
Asset fair value		0	0	0
Fair Value, Inputs, Level 2 [Member]
Asset fair value		13,322,000	13,322,000	12,113,000
Fair Value, Inputs, Level 3 [Member]
Asset fair value		0	0	0
Asset fair value		13,322,000	13,322,000	12,113,000
Fair value gain (loss)		$ (347,000)	$ (722,000)	$ (632,000)

[1] Represents the carrying value and related specific reserves on loans for which adjustments are based on the appraised value of the collateral. The carrying value of loans fully charged-off is zero.

[2] Represents the fair value and related losses of foreclosed real estate and other collateral owned that were measured at fair value subsequent to their initial classification as foreclosed assets.