Income Taxes - Differences Between Statutory Income Tax Rate and Effective Income Tax Rate (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Increase (decrease) resulting from:
Tax at statutory rate	$ (31)	$ (122)	$ 165	$ (416)
Tax-exempt income from municipal bonds	(5)	(5)	(15)	(15)
Dividend received exclusion	(5)	(5)	(16)	(15)
Release of unrecognized tax benefit	0	(34)	0	(34)
Other	(8)	5	(8)	(1)
Total provision (benefit) for income taxes	$ (49)	$ (161)	$ 126	$ (481)
Increase (decrease) resulting from:
Tax at statutory rate	21.00%	21.00%	21.00%	21.00%
Tax-exempt income from municipal bonds, Percent	3.40%	0.90%	(1.90%)	0.80%
Dividend received exclusion, Percent	3.40%	0.90%	(2.00%)	0.80%
Release of unrecognized tax benefit, Percent	0.00%	5.90%	0.00%	1.70%
Other	5.30%	(0.80%)	(1.10%)	0.00%
Provision for income taxes	33.10%	27.90%	16.00%	24.30%