Income Taxes - Income Tax Reconciliation (Details) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Income Tax Disclosure [Abstract] | |||
| Federal income tax rate (as a percent) | 35.00% | 35.00% | 35.00% |
| Reconciling items: | |||
| Tax exempt interest (as a percent) | (9.40%) | (8.00%) | (12.30%) |
| Dividend received deduction (as a percent) | (1.70%) | (1.40%) | (2.20%) |
| Non deductible health insurer fee (as a percent) | 1.00% | 0.70% | 0.00% |
| Other (as a percent) | 0.20% | 0.10% | 0.10% |
| Effective income tax rate: (as a percent) | 25.10% | 26.40% | 20.60% |