Note 7 - Investment and Equity Securities - Amortized Cost and Fair Value of Debt Securities by Contractual Maturity (Details) $ in Thousands	Mar. 31, 2018 USD ($)
Due in one year or less, amortized costs	$ 4,252
Due in one year or less, fair value	4,303
Due after one year through five years, amortized costs	7,607
Due after one year through five years, fair value	7,713
Due after five years through ten years, amortized costs	12,489
Due after five years through ten years, fair value	12,420
Due after ten years, amortized costs	67,384
Due after ten years, fair value	66,826
Amortized costs	91,732
Fair Value	$ 91,262