Intangible Assets - Indefinite-lived Intangible Assets (Detail) - USD ($) $ in Millions |
Dec. 31, 2015 |
Dec. 31, 2014 |
|---|---|---|
| Indefinite-lived Intangible Assets [Line Items] | ||
| Indefinite-lived intangible assets | $ 17,108 | $ 16,988 |
| Management Contracts [Member] | ||
| Indefinite-lived Intangible Assets [Line Items] | ||
| Indefinite-lived intangible assets | 15,699 | 15,579 |
| Trade Names / Trademarks [Member] | ||
| Indefinite-lived Intangible Assets [Line Items] | ||
| Indefinite-lived intangible assets | 1,403 | 1,403 |
| License [Member] | ||
| Indefinite-lived Intangible Assets [Line Items] | ||
| Indefinite-lived intangible assets | $ 6 | $ 6 |