Investment Information - Limited partnership interests (Details) - USD ($) $ in Millions		Sep. 30, 2025	Dec. 31, 2024
Schedule of Equity Method Investments [Line Items]
Maximum Exposure to Loss		$ 6,232	$ 6,028
Aggregate unfunded commitments		3,700	4,400
Equity method investments
Schedule of Equity Method Investments [Line Items]
Maximum Exposure to Loss	[1]	6,232	5,980
Aggregate unfunded commitments		3,700	4,300
Fair value option
Schedule of Equity Method Investments [Line Items]
Maximum Exposure to Loss	[2]	0	48
Aggregate unfunded commitments		$ 15	$ 21

[1] Aggregate unfunded commitments were $3.7 billion at September 30, 2025, compared to $4.3 billion at December 31, 2024.

[2] Aggregate unfunded commitments were $15 million at September 30, 2025, compared to $21 million at December 31, 2024