Note 12 - 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, 2017		Sep. 30, 2016		Sep. 30, 2017		Sep. 30, 2016		Dec. 31, 2016		Dec. 31, 2015
Total at Fair Value	$ 58,974				$ 58,974				$ 37,981
Total Losses	417		$ (19)		1,044		$ 428		1,307		$ 2,507
Fair Value, Inputs, Level 1 [Member]
Total at Fair Value
Fair Value, Inputs, Level 2 [Member]
Total at Fair Value	6,317				6,317				6,006
Fair Value, Inputs, Level 3 [Member]
Total at Fair Value	52,657				52,657				31,975
Impaired Loans [Member]
Total at Fair Value	45,312				45,312				23,936
Total Losses					25				322		1,550
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	45,312				45,312				23,936
Impaired Loans [Member] | Commercial Portfolio Segment [Member]
Total at Fair Value	12,525				12,525				2,813
Total Losses					25				322		806
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	12,525				12,525				2,813
Impaired Loans [Member] | Commercial Real Estate Portfolio Segment [Member]
Total at Fair Value	21,997				21,997				9,444
Total Losses											598
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	21,997				21,997				9,444
Impaired Loans [Member] | Residential Mortgage and Equity Lines Portfolio Segment [Member]
Total at Fair Value	10,790				10,790				11,679
Total Losses											146
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	10,790				10,790				11,679
Other Real Estate Owned [Member]
Total at Fair Value	10,639	[1]			10,639	[1]			10,378	[2]
Total Losses	405	[1]	(206)	[1]	654	[1]	9	[1]	9	[2]	404	[2]
Other Real Estate Owned [Member] | Fair Value, Inputs, Level 1 [Member]
Total at Fair Value		[1]				[1]				[2]
Other Real Estate Owned [Member] | Fair Value, Inputs, Level 2 [Member]
Total at Fair Value	6,317	[1]			6,317	[1]			6,006	[2]
Other Real Estate Owned [Member] | Fair Value, Inputs, Level 3 [Member]
Total at Fair Value	4,322	[1]			4,322	[1]			4,372	[2]
Equity Investments [Member]
Total at Fair Value	3,023				3,023				3,667
Total Losses	12		$ 187		365		$ 419		976		$ 553
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	$ 3,023				$ 3,023				$ 3,667

[1] Other real estate owned balance of $18.1 million in the condensed consolidated balance sheet is net of estimated disposal costs.

[2] Other real estate owned balance of $20.1 million in the condensed consolidated balance sheet is net of estimated disposal costs.