Note 8 - Regulatory Capital Requirements and Restrictions on Dividends (Details)	6 Months Ended
	Jun. 30, 2018
REGULATORY CAPITAL REQUIREMENTS
Annual Phase in Percentage Of Capital Conservation Buffer	0.625%
Capital Required for Capital Adequacy to Risk Weighted Assets with Capital Conservation Buffer Fully Phased in	10.50%
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets with Capital Conservation Buffer Fully Phased in	8.50%
Common Equity Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets with Capital Conservation Buffer Fully Phased in	7.00%