Variable Interest Entities (Details) - USD ($) $ in Millions		Sep. 30, 2023	Dec. 31, 2022
Variable Interest Entity [Line Items]
Total VIE Assets		$ 55,227	$ 47,990
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Total VIE Assets		2,874	3,595
Remaining Coverage, Amount		353
Variable Interest Entity, Not Primary Beneficiary | 2017-1 Ltd. (Oct-17)
Variable Interest Entity [Line Items]
Total VIE Assets		0	37
Variable Interest Entity, Not Primary Beneficiary | 2018-1 Ltd. (Apr-18)
Variable Interest Entity [Line Items]
Total VIE Assets		51	90
Variable Interest Entity, Not Primary Beneficiary | 2018-3 Ltd. (Oct-18)
Variable Interest Entity [Line Items]
Total VIE Assets		154	199
Variable Interest Entity, Not Primary Beneficiary | 2019-1 Ltd. (Mar-19)
Variable Interest Entity [Line Items]
Total VIE Assets		80	108
Variable Interest Entity, Not Primary Beneficiary | 2019-2 Ltd. (Apr-19)
Variable Interest Entity [Line Items]
Total VIE Assets		265	325
Variable Interest Entity, Not Primary Beneficiary | 2019-3 Ltd. (Jul-19)
Variable Interest Entity [Line Items]
Total VIE Assets		120	223
Variable Interest Entity, Not Primary Beneficiary | 2019-4 Ltd. (Oct-19)
Variable Interest Entity [Line Items]
Total VIE Assets		218	266
Variable Interest Entity, Not Primary Beneficiary | 2020-2 Ltd. (Sep-20)
Variable Interest Entity [Line Items]
Total VIE Assets		54	105
Variable Interest Entity, Not Primary Beneficiary | 2020-3 Ltd. (Nov-20)
Variable Interest Entity [Line Items]
Total VIE Assets		183	244
Remaining Coverage, Amount	[1]	4
Variable Interest Entity, Not Primary Beneficiary | 2020-4 Ltd. (Dec-20)
Variable Interest Entity [Line Items]
Total VIE Assets		67	98
Remaining Coverage, Amount	[1]	2
Variable Interest Entity, Not Primary Beneficiary | 2021-1 Ltd. (Mar-21)
Variable Interest Entity [Line Items]
Total VIE Assets		388	467
Remaining Coverage, Amount	[1]	17
Variable Interest Entity, Not Primary Beneficiary | 2021-2 Ltd. (Jun-21)
Variable Interest Entity [Line Items]
Total VIE Assets		380	458
Remaining Coverage, Amount	[1]	58
Variable Interest Entity, Not Primary Beneficiary | 2021-3 Ltd. (Sep-21)
Variable Interest Entity [Line Items]
Total VIE Assets		444	490
Remaining Coverage, Amount	[1]	116
Variable Interest Entity, Not Primary Beneficiary | 2022-1 Ltd. (Jan-22)
Variable Interest Entity [Line Items]
Total VIE Assets		269	284
Remaining Coverage, Amount	[1]	30
Variable Interest Entity, Not Primary Beneficiary | 2022-2 Ltd. (Sep-22)
Variable Interest Entity [Line Items]
Total VIE Assets		201	$ 201
Remaining Coverage, Amount	[1]	$ 126

[1] Coverage from a separate panel of reinsurers remaining at September 30, 2023.