Note 7 - Stockholders' Equity (Details Textual) - USD ($) $ / shares in Units, $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Common Stock, Shares Authorized (in shares)	450,000,000	450,000,000
Common Stock, Par or Stated Value Per Share (in dollars per share)	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized (in shares)	50,000,000	50,000,000
Preferred Stock, Par or Stated Value Per Share (in dollars per share)	$ 0.01	$ 0.01
Common Stock, Shares, Outstanding, Ending Balance (in shares)	35,587,851	35,534,558
Preferred Stock, Shares Outstanding, Ending Balance (in shares)	0	0
Stock Repurchase Program, Authorized Amount		$ 50