Subsequent Events (Details) - $ / shares |
12 Months Ended | ||||
|---|---|---|---|---|---|
Feb. 15, 2016 |
Nov. 04, 2015 |
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Subsequent Event [Line Items] | |||||
| Dividends declared per common share (in dollars per share) | $ 0.14 | $ 0.53 | $ 0.46 | $ 0.38 | |
| Subsequent event | |||||
| Subsequent Event [Line Items] | |||||
| Dividends declared per common share (in dollars per share) | $ 0.14 | ||||
| Subsequent event | Preference shares - Series A | |||||
| Subsequent Event [Line Items] | |||||
| Dividends declared per Preference share (in dollars per share) | 0.515625 | ||||
| Subsequent event | Preference shares - Series B | |||||
| Subsequent Event [Line Items] | |||||
| Dividends declared per Preference share (in dollars per share) | 0.90625 | ||||
| Subsequent event | Preference shares - Series C | |||||
| Subsequent Event [Line Items] | |||||
| Dividends declared per Preference share (in dollars per share) | $ 0.54427083 | ||||