Insurance Liabilities - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Liability for Future Policy Benefit, by Product Segment [Line Items]
Contractual deductible recoverable amount	$ 12,100	$ 12,300
Collateral held for deductible recoverable amounts	8,600	8,600
Liability for unpaid losses and loss adjustment expenses, allowance for credit losses	14	14
Prior years, excluding discount and amortization of deferred gain	530	171	$ 90
Net loss reserve discount	$ 1,278	876
Tabular discount rate (as a percent)	45.00%
Workers compensation tabular discount amount	$ 314	260
Workers compensation non tabular discount amount	964	616
Net loss reserve discount charge	$ (703)	(193)	516
Gross insurance in force (as a percent)	0.70%
Premiums on life insurance (as a percent)	1.30%
Minimum
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest rate (asva percent)	0.20%
Withdrawal charges (as a percent)	0.00%
Maximum
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest rate (asva percent)	14.60%
Withdrawal charges (as a percent)	9.00%
NICO
Liability for Future Policy Benefit, by Product Segment [Line Items]
Amortization of deferred gain on retroactive reinsurance	$ 189	$ 137	$ 196
New York
Liability for Future Policy Benefit, by Product Segment [Line Items]
Nontabular discount rate (as a percent)	5.00%