Income Taxes - Differences Between Statutory Income Tax Rate and Effective Income Tax Rate (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Increase (decrease) resulting from:
Tax at statutory rate	$ (122)	$ 39	$ (416)	$ 383
Tax-exempt income from municipal bonds	(5)	(5)	(15)	(15)
Dividend received exclusion	(5)	(5)	(15)	(14)
Release of unrecognized tax benefit	(34)	0	(34)	0
Other	5	2	(1)	(6)
Total provision (benefit) for income taxes	$ (161)	$ 31	$ (481)	$ 348
Increase (decrease) resulting from:
Tax at statutory rate	21.00%	21.00%	21.00%	21.00%
Tax-exempt income from municipal bonds, Percent	0.90%	(2.70%)	0.80%	(0.80%)
Dividend received exclusion, Percent	0.90%	(2.70%)	0.80%	(0.80%)
Release of unrecognized tax benefit, Percent	5.90%	0.00%	1.70%	0.00%
Other	(0.90%)	1.20%	0.00%	(0.30%)
Provision for income taxes	27.80%	16.80%	24.30%	19.10%