Fair Value Measurements - Measured on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Assets
Derivatives	$ 52	$ 18
Liabilities
Derivatives	22	23
Mutual funds
Assets
Fair value of investments measured on recurring basis	1,335	1,363
U.S. Government securities
Assets
Fair value of investments measured on recurring basis	92	99
Other securities
Assets
Fair value of investments measured on recurring basis	555	319
Level 1
Assets
Derivatives	0	0
Liabilities
Derivatives	0	0
Level 1 \| Mutual funds
Assets
Fair value of investments measured on recurring basis	1,335	1,363
Level 1 \| U.S. Government securities
Assets
Fair value of investments measured on recurring basis	0	0
Level 1 \| Other securities
Assets
Fair value of investments measured on recurring basis	341	171
Level 2
Assets
Derivatives	52	18
Liabilities
Derivatives	22	23
Level 2 \| Mutual funds
Assets
Fair value of investments measured on recurring basis	0	0
Level 2 \| U.S. Government securities
Assets
Fair value of investments measured on recurring basis	92	99
Level 2 \| Other securities
Assets
Fair value of investments measured on recurring basis	214	148
NAV \| Other commingled funds
Liabilities
Assets measured at NAV	$ 20	$ 19

Fair value of investment other than investment in equity security, investment in debt security and equity method investment. Includes, but is not limited to, investment in certain entities that calculate net asset value per share. Example includes, but is not limited to, investment in hedge fund, venture capital fund, private equity fund, and real estate partnership or fund.

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

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