Note 11 - Preferred Stock and Common Stock (Details Textual) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended
	Feb. 28, 2015	Mar. 31, 2017	Dec. 31, 2016
Common Stock, Par or Stated Value Per Share		$ 0.01	$ 0.01
ATM Program, Amount Available		$ 211.9
ATM Program [Member]
Common Stock, Par or Stated Value Per Share	$ 0.01
Maximum Aggregate Sales Price	$ 500.0