Investments (Schedule Of Components Of Restricted Assets) (Detail) - USD ($) $ in Millions |
Jun. 30, 2015 |
Dec. 31, 2014 |
|---|---|---|
| Investments, Debt and Equity Securities [Abstract] | ||
| Trust funds | $ 11,085 | $ 10,838 |
| Deposits with non-U.S. regulatory authorities | 2,263 | 2,305 |
| Assets pledged under repurchase agreements | 1,458 | 1,431 |
| Deposits with U.S. regulatory authorities | 1,327 | 1,345 |
| Other pledged assets | 398 | 457 |
| Total restricted assets | $ 16,531 | $ 16,376 |