Note 19 - Regulatory Matters (Details Textual) - USD ($) $ in Billions	Dec. 31, 2019		Jan. 01, 2019	Dec. 31, 2018	[1]	Jul. 31, 2013
Common Equity Tier 1 Capital Required for Capital Adequacy to Risk Weighted Assets	7.00%	[1]		6.375%		4.50%
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	8.50%	[1]		7.875%		6.00%
Capital Required for Capital Adequacy to Risk Weighted Assets	10.50%	[1]		9.875%		8.00%
Tier One Leverage Capital Required for Capital Adequacy to Average Assets	4.00%	[1]		4.00%		4.00%
Capital Conservation Buffer			2.50%
Community Bank Leverage Ratio Framework, Minimum Tier 1 Leverage Ratio	9.00%
Community Bank Leverage Ratio Framework, Maximum Total Consolidated Assets	$ 10

[1] The adequately capitalized thresholds in the table above are reflected on a fully phased-in basis, which occurred in January 2019.