Fair Value Disclosures - Investments in Certain Entities Calculate Net Asset Value per Share (Parenthetical) (Detail) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share Line Items
Total Unfunded Commitments	$ 1,238	$ 1,215
Investment, Type [Extensible Enumeration]	Real Assets Funds [Member]	Real Assets Funds [Member]
Real Assets Funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share Line Items
Total Unfunded Commitments	$ 759	$ 750
Total remaining Unfunded Commitments	$ 746	$ 736