Note 11 - Fair Value Measurements - Financial Assets and Liabilities Measured On a Non-recurring Basis (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended			12 Months Ended
	Sep. 30, 2016		Sep. 30, 2015	Sep. 30, 2016		Sep. 30, 2015	Dec. 31, 2015	Dec. 31, 2014
Impaired Loans [Member] | Commercial Portfolio Segment [Member] | Fair Value, Inputs, Level 1 [Member]
Total at Fair Value
Impaired Loans [Member] | Commercial Portfolio Segment [Member] | Fair Value, Inputs, Level 2 [Member]
Total at Fair Value
Impaired Loans [Member] | Commercial Portfolio Segment [Member] | Fair Value, Inputs, Level 3 [Member]
Total at Fair Value	1,897			1,897			6,317
Impaired Loans [Member] | Commercial Portfolio Segment [Member]
Total at Fair Value	1,897			1,897			6,317
Total Losses			$ 575			$ 3,380	806	$ 17
Impaired Loans [Member] | Commercial Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 1 [Member]
Total at Fair Value
Impaired Loans [Member] | Commercial Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 2 [Member]
Total at Fair Value
Impaired Loans [Member] | Commercial Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 3 [Member]
Total at Fair Value	9,041			9,041			20,359
Impaired Loans [Member] | Commercial Real Estate Portfolio Segment [Member]
Total at Fair Value	9,041			9,041			20,359
Total Losses						654	598	3,914
Impaired Loans [Member] | Residential Mortgage and Equity Lines Portfolio Segment [Member] | Fair Value, Inputs, Level 1 [Member]
Total at Fair Value
Impaired Loans [Member] | Residential Mortgage and Equity Lines Portfolio Segment [Member] | Fair Value, Inputs, Level 2 [Member]
Total at Fair Value
Impaired Loans [Member] | Residential Mortgage and Equity Lines Portfolio Segment [Member] | Fair Value, Inputs, Level 3 [Member]
Total at Fair Value	13,139			13,139			13,009
Impaired Loans [Member] | Residential Mortgage and Equity Lines Portfolio Segment [Member]
Total at Fair Value	13,139			13,139			13,009
Total Losses						146	146	27
Impaired Loans [Member] | Fair Value, Inputs, Level 1 [Member]
Total at Fair Value
Impaired Loans [Member] | Fair Value, Inputs, Level 2 [Member]
Total at Fair Value
Impaired Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Total at Fair Value	24,077			24,077			39,685
Impaired Loans [Member]
Total at Fair Value	24,077			24,077			39,685
Total Losses			575			4,180	1,550	3,958
Other Real Estate Owned [Member] | Fair Value, Inputs, Level 1 [Member]
Total at Fair Value		[1]			[1]
Other Real Estate Owned [Member] | Fair Value, Inputs, Level 2 [Member]
Total at Fair Value	3,095	[1]		3,095	[1]		10,047
Other Real Estate Owned [Member] | Fair Value, Inputs, Level 3 [Member]
Total at Fair Value	4,372	[1]		4,372	[1]		4,235
Other Real Estate Owned [Member]
Total at Fair Value	7,467	[1]		7,467	[1]		14,282
Total Losses	(206)		179	9		404	404	202
Equity Investments [Member] | Fair Value, Inputs, Level 1 [Member]
Total at Fair Value
Equity Investments [Member] | Fair Value, Inputs, Level 2 [Member]
Total at Fair Value
Equity Investments [Member] | Fair Value, Inputs, Level 3 [Member]
Total at Fair Value	4,291			4,291			4,922
Equity Investments [Member]
Total at Fair Value	4,291			4,291			4,922
Total Losses	187		81	419		408	553	436
Fair Value, Inputs, Level 1 [Member]
Total at Fair Value
Fair Value, Inputs, Level 2 [Member]
Total at Fair Value	3,095			3,095			10,047
Fair Value, Inputs, Level 3 [Member]
Total at Fair Value	32,740			32,740			48,842
Total at Fair Value	35,835			35,835			58,889
Total Losses	$ (19)		$ 835	$ 428		$ 4,992	$ 2,507	$ 4,596

[1] Other real estate owned balance of $21.0 million in the condensed consolidated balance sheet is net of estimated disposal costs.