Income Taxes - Schedule of Reconciliation of the Statutory Federal Income Tax Rate to the Effective Income Tax Rate (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Effective Income Tax Rate Reconciliation, Amount [Abstract]
(Loss) income before income taxes	$ (348)	$ (1,830)	$ 6,466
Statutory federal income tax rate on income from operations	(73)	(384)	1,357
Tax credits	(47)	(55)	(42)
Tax-exempt income	(23)	(17)	(18)
U.S. shareholder’s tax (benefit) expense	(17)	13	4
Share-based payments	(14)	(22)	(18)
State income taxes	(7)	0	13
Dividend received deduction	(4)	(7)	(5)
Uncertain tax positions	33	2	0
Change in valuation allowance	6	10	(3)
Other	11	(28)	4
Total income tax (benefit) expense	$ (135)	$ (488)	$ 1,292
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation
Statutory federal income tax rate on income from operations	21.00%	21.00%	21.00%
Tax credits	13.50%	3.00%	(0.60%)
Tax-exempt income	6.60%	0.90%	(0.30%)
U.S. shareholder’s tax (benefit) expense	4.90%	(0.70%)	0.10%
Share-based payments	4.00%	1.20%	(0.30%)
State income taxes	2.00%	0.00%	0.20%
Dividend received deduction	1.10%	0.40%	(0.10%)
Uncertain tax positions	(9.50%)	(0.10%)	0.00%
Change in valuation allowance	(1.70%)	(0.60%)	(0.10%)
Other	(3.10%)	1.60%	0.10%
Effective income tax rate on income from operations	38.80%	26.70%	20.00%

Effective Income Tax Rate Reconciliation, Shareholder Tax Benefit, Amount

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Sum of operating profit and non-operating income (expense) and income (loss) from equity method investments before income taxes.

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in the valuation allowance for deferred tax assets.

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to state and local income tax expense (benefit), net of federal tax expense (benefit).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to tax credits. Including, but not limited to, research credit, foreign tax credit, investment tax credit, and other tax credits.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to increase (decrease) in the valuation allowance for deferred tax assets.

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The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations.

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Amount of reported income tax expense (benefit) in excess of (less than) expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operation, attributable to nondeductible expense for award under share-based payment arrangement. Includes, but is not limited to, expense determined to be nondeductible upon grant or after for award under share-based payment arrangement.

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