Fair Value Disclosures - Investments in Certain Entities Calculate Net Asset Value per Share (Detail) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
Jun. 30, 2025	Dec. 31, 2024
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total Unfunded Commitments	$ 1,246	$ 1,215
Fair Value Measured at NAV per share [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	2,636	2,579
Hedge Funds/Funds of Hedge Funds/Other [Member] \| Consolidated Variable Interest Entities [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total Unfunded Commitments	$ 55	$ 58
Redemption Frequency (Quarterly)	78.00%	64.00%
Redemption Frequency (Not Redeemable)	22.00%	36.00%
Hedge Funds/Funds of Hedge Funds/Other [Member] \| Consolidated Variable Interest Entities [Member] \| Fair Value Measured at NAV per share [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 175	$ 92
Private Equity Funds [Member] \| Consolidated Variable Interest Entities [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total Unfunded Commitments	39	42
Private Equity Funds [Member] \| Consolidated Variable Interest Entities [Member] \| Fair Value Measured at NAV per share [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	85	7
Real Assets Funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total Unfunded Commitments	724	750
Real Assets Funds [Member] \| Consolidated Variable Interest Entities [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total Unfunded Commitments	32	40
Real Assets Funds [Member] \| Consolidated Variable Interest Entities [Member] \| Fair Value Measured at NAV per share [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 151	$ 175
Other Funds [Member] \| Consolidated Variable Interest Entities [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Redemption Notice Period, days	90 days	90 days
Equity Method Investments [Member] \| Hedge Funds/Funds of Hedge Funds/Other [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total Unfunded Commitments	$ 135	$ 138
Redemption Frequency (Daily)	2.00%	2.00%
Redemption Frequency (Monthly)	2.00%	2.00%
Redemption Frequency (Quarterly)	16.00%	10.00%
Redemption Frequency (Not Redeemable)	82.00%	88.00%
Equity Method Investments [Member] \| Hedge Funds/Funds of Hedge Funds/Other [Member] \| Fair Value Measured at NAV per share [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 459	$ 552
Equity Method Investments [Member] \| Hedge Funds/Funds of Hedge Funds/Other [Member] \| Minimum [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Redemption Notice Period, days	1 day	1 day
Equity Method Investments [Member] \| Hedge Funds/Funds of Hedge Funds/Other [Member] \| Maximum [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Redemption Notice Period, days	90 days	90 days
Equity Method Investments [Member] \| Private Equity Funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total Unfunded Commitments	$ 293	$ 227
Equity Method Investments [Member] \| Private Equity Funds [Member] \| Fair Value Measured at NAV per share [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	753	1,060
Equity Method Investments [Member] \| Real Assets Funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total Unfunded Commitments	$ 692	$ 710
Redemption Frequency (Quarterly)	6.00%	7.00%
Redemption Frequency (Not Redeemable)	94.00%	93.00%
Redemption Notice Period, days	60 days	60 days
Equity Method Investments [Member] \| Real Assets Funds [Member] \| Fair Value Measured at NAV per share [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 594	$ 520
Equity Method Investments [Member] \| Investments Related To Deferred Cash Compensation Plans [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total Unfunded Commitments	0	0
Equity Method Investments [Member] \| Investments Related To Deferred Cash Compensation Plans [Member] \| Fair Value Measured at NAV per share [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 284	$ 173
Equity Method Investments [Member] \| Investments Related To Deferred Cash Compensation Plans [Member] \| Minimum [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Redemption Notice Period, days	1 day	1 day
Equity Method Investments [Member] \| Investments Related To Deferred Cash Compensation Plans [Member] \| Maximum [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Redemption Notice Period, days	90 days	90 days
Other Investments [Member] \| Private Credit Fund [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total Unfunded Commitments	$ 0
Redemption Notice Period, days	30 days
Other Investments [Member] \| Private Credit Fund [Member] \| Fair Value Measured at NAV per share [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 135

Fair value measured recurring basis using net asset per share value redemption frequency (daily).

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Fair value measured recurring basis using net asset per share value redemption frequency not redeemable.

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- Definition

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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- Definition

Notice period the entity is required to deliver before it can redeem an investment calculated using net asset value per share, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Includes, but is not limited to, investments calculated by per unit, per membership interest, other equity or ownership interest and alternative investments.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The amount of unfunded commitments for which the entity is obligated, to those certain investments for which net asset value per share is calculated (including by unit, membership interest, or other equity (ownership interest) unit measure) (alternative investments).

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