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, 2024	Dec. 31, 2023	Dec. 31, 2022
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income (loss) before income taxes	$ 5,761	$ (348)	$ (1,830)
Statutory federal income tax rate on income from operations	1,210	(73)	(384)
State income taxes	54	(7)	0
Change in valuation allowance	8	6	10
Tax credits	(42)	(47)	(55)
Share-based payments	(30)	(14)	(22)
Tax-exempt income	(29)	(23)	(17)
Uncertain tax positions	(8)	33	2
Dividend received deduction	(1)	(4)	(7)
U.S. shareholder's tax (benefit) expense	0	(17)	13
Other	0	11	(28)
Total income tax expense (benefit)	$ 1,162	$ (135)	$ (488)
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation
Statutory federal income tax rate on income from operations	21.00%	21.00%	21.00%
State income taxes	0.90%	2.00%	0.00%
Change in valuation allowance	0.10%	(1.70%)	(0.60%)
Tax credits	(0.70%)	13.50%	3.00%
Share-based payments	(0.50%)	4.00%	1.20%
Tax-exempt income	(0.50%)	6.60%	0.90%
Uncertain tax positions	(0.10%)	(9.50%)	(0.10%)
Dividend received deduction	0.00%	1.10%	0.40%
U.S. shareholder's tax (benefit) expense	0.00%	4.90%	(0.70%)
Other	0.00%	(3.10%)	1.60%
Effective income tax rate on income from operations	20.20%	38.80%	26.70%