|
Fair Value Measurements - Measured Under Certain Conditions (Details) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | |
|---|---|---|
|
Mar. 31, 2015
|
Mar. 31, 2014
|
|
| Financing Receivable, Impaired [Line Items] | ||
| Realized investment losses on impaired commercial mortgage loans and real estate entities | $ 4 | $ 4 |
| Maximum [Member] | ||
| Financing Receivable, Impaired [Line Items] | ||
| Impaired commercial mortgage loans and real estate entities as a percent of total investments | 1.00% | 1.00% |