Note 15 - Fair Value Measurements - Change in Fair Value Measurement Impacts Net Income (Details) - Valuation, Market Approach [Member]	Dec. 31, 2020
Pull-through Rate [Member] | Interest Rate Contract [Member]
Derivative asset (liability)	0.8702	[1]
Pull-through Rate [Member] | Forward Contract [Member]
Derivative asset (liability)	0.8702	[1]
Current Reference Price [Member] | Interest Rate Contract [Member] | Minimum [Member]
Derivative asset (liability)	1.0191
Current Reference Price [Member] | Interest Rate Contract [Member] | Maximum [Member]
Derivative asset (liability)	1.0302
Current Reference Price [Member] | Interest Rate Contract [Member] | Weighted Average [Member]
Derivative asset (liability)	1.0255	[2]
Current Reference Price [Member] | Forward Contract [Member] | Minimum [Member]
Derivative asset (liability)	1.0191
Current Reference Price [Member] | Forward Contract [Member] | Maximum [Member]
Derivative asset (liability)	1.0319
Current Reference Price [Member] | Forward Contract [Member] | Weighted Average [Member]
Derivative asset (liability)	1.0267	[2]

[1] All contracts are valued using the same pull-through rate.

[2] Current reference prices were weighted by the relative amount of the loan.