Note 7 - Fair Value Measurement (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Liabilities, Fair Value Disclosure, Nonrecurring	$ 0	$ 0
Minimum [Member]
Federal Funds Maturity	1 day
Maximum [Member]
Federal Funds Maturity	3 days