Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions |
Dec. 31, 2014 |
Dec. 31, 2013 |
|---|---|---|
| Investments | $ 1,662.7 | $ 3,481.8 |
| Class A Ordinary Shares [Member] | ||
| Common stock, par value (in dollars per share) | $ 0.01 | $ 0.01 |
| Common stock, issued (in shares) | 251,167,686 | 222,081,117 |
| Common stock, outstanding (in shares) | 251,167,686 | 222,081,117 |
| Class B Ordinary Shares [Member] | ||
| Common stock, par value (in dollars per share) | $ 0.01 | $ 0.01 |
| Common stock, issued (in shares) | 10,139,184 | 10,147,184 |
| Common stock, outstanding (in shares) | 10,139,184 | 10,147,184 |
| Class C Ordinary Shares [Member] | ||
| Common stock, par value (in dollars per share) | $ 0.01 | $ 0.01 |
| Common stock, issued (in shares) | 630,353,372 | 556,221,669 |
| Common stock, outstanding (in shares) | 630,353,372 | 556,221,669 |