Note 6 - Purchase of Financial Assets (Details Textual) - USD ($) $ in Millions	12 Months Ended	44 Months Ended
	Dec. 31, 2017	Dec. 31, 2017
Loan Purchase Agreement Financial Asset for Which Transfer Is Accounted as a Purchase Total Commitment to Purchase	$ 50.0
Loan Purchase Agreement Financial Asset for Which Transfer is Accounted as a Purchase Par Value Purchased		$ 118.3
Loan Purchase Agreement Financial Asset for Which Transfer Is Accounted as a Purchase Net Discount Premium		71.9
Payments for Loans		$ 46.4