Income Taxes - Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Tax provision at U.S. federal statutory rate	$ 137	$ 114
Nontaxable investment income	(11)	(9)
Other	2	4
Income tax expense	118	98
Effective Income Tax Rate Reconciliation, Tax Expense (Benefit), Share-based Payment Arrangement, Amount	(12)	(10)
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Amount	$ 6	$ 7