Investments (Narrative) (Details) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2015
USD ($)
security
|
Dec. 31, 2014
USD ($)
security
|
Dec. 31, 2013
USD ($)
|
|
| Investments [Abstract] | |||
| Maximum restricted level of investment upon stockholders equity | 10.00% | 10.00% | |
| Gross realized gains on investments | $ 6.7 | $ 0.6 | $ 10.9 |
| Gross realized losses on investments | 0.9 | 0.2 | 0.4 |
| Proceeds from sale of available-for-sale securities | $ 51.7 | $ 15.3 | $ 33.4 |
| Number of debt security positions | security | 39 | 24 | |
| Recognized other-than-temporary losses on our debt securities portfolio | $ 3.3 | ||
| Securities pledged for the benefit of various state insurance departments and reinsurers | $ 17.6 | $ 20.3 | |