Note 9 - Purchase of Financial Assets (Details Textual) - USD ($) $ in Millions	6 Months Ended	50 Months Ended
	Jun. 30, 2018	Jun. 30, 2018
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		$ 127.3
Loan Purchase Agreement Financial Asset for Which Transfer Is Accounted as a Purchase Net Discount Premium		82.5
Payments for Loans		$ 44.8