Fair Value Measurements (details) - USD ($) $ in Millions |
Mar. 31, 2017 |
Dec. 31, 2016 |
|---|---|---|
| Fair Value Measurements disclosure | ||
| Percent of fixed maturities for which a pricing service estimates fair value | 98.00% | 98.00% |
| Fair value of the fixed maturities for which the Company used an internal pricing matrix | $ 179 | $ 99 |
| Fair value of the fixed maturities for which the Company received a broker quote | $ 83 | $ 85 |
| Percent of short-term securities for which a pricing service estimates fair value | 98.00% | 98.00% |
| Percent of debt, including commercial paper, for which a pricing service estimates fair value | 100.00% | 100.00% |