Note 15 - Fair Value Measurements - Financial Assets and Liabilities Measured on a Non-recurring Basis (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Total at Fair Value	$ 73,493		$ 37,981
Total Losses	874		1,307		$ 2,507
Fair Value, Inputs, Level 1 [Member]
Total at Fair Value
Fair Value, Inputs, Level 2 [Member]
Total at Fair Value	5,677		6,006
Fair Value, Inputs, Level 3 [Member]
Total at Fair Value	67,816		31,975
Impaired Loans [Member]
Total at Fair Value	60,911		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	60,911		23,936
Impaired Loans [Member] | Commercial Portfolio Segment [Member]
Total at Fair Value	18,097		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	18,097		2,813
Impaired Loans [Member] | Commercial Real Estate Portfolio Segment [Member]
Total at Fair Value	31,459		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	31,459		9,444
Impaired Loans [Member] | Residential Mortgage and Equity Lines Portfolio Segment [Member]
Total at Fair Value	11,355		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	11,355		11,679
Other Real Estate Owned [Member]
Total at Fair Value	9,999	[1]	10,378	[2]
Total Losses	457	[1]	9	[2]	404	[2]
Other Real Estate Owned [Member] | Fair Value, Inputs, Level 1 [Member]
Total at Fair Value		[1]		[2]
Other Real Estate Owned [Member] | Fair Value, Inputs, Level 2 [Member]
Total at Fair Value	5,677	[1]	6,006	[2]
Other Real Estate Owned [Member] | Fair Value, Inputs, Level 3 [Member]
Total at Fair Value	4,322	[1]	4,372	[2]
Equity Investments [Member]
Total at Fair Value	2,583		3,667
Total Losses	392		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	$ 2,583		$ 3,667

[1] Other real estate owned balance of $9.4 million in the Consolidated Balance Sheets 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.