Note 1 - Summary of Significant Accounting Policies - Estimated Useful Lives and Methods of Depreciation (Details) |
12 Months Ended |
|---|---|
Dec. 31, 2016 | |
| Banking Premises [Member] | |
| Property, plant and equipment, depreciation method | Straight-Line and Accelerated |
| Banking Premises [Member] | Minimum [Member] | |
| Property, plant and equipment, useful life (Year) | 15 years |
| Banking Premises [Member] | Maximum [Member] | |
| Property, plant and equipment, useful life (Year) | 40 years |
| Furniture and Equipment [Member] | |
| Property, plant and equipment, depreciation method | Straight-Line and Accelerated |
| Furniture and Equipment [Member] | Minimum [Member] | |
| Property, plant and equipment, useful life (Year) | 5 years |
| Furniture and Equipment [Member] | Maximum [Member] | |
| Property, plant and equipment, useful life (Year) | 10 years |