Consolidated Balance Sheets (Parentheticals) - $ / shares |
Dec. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Statement Of Financial Position [Abstract] | ||
| Preferred shares, no par value (in dollars per share) | $ 0 | $ 0 |
| Common shares, par value (in dollars per share) | $ 0.01 | $ 0.01 |