Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and Cash Equivalents, Fair Value Disclosure	$ 987	$ 1,139
Finance receivable	92	98
Loss and loss expense reserves	3,027	3,014
Life Policy Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Finance receivable	30	31
Investment contract reserves:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Loss and loss expense reserves	1,580	1,586
Investment contract reserves: | Deferred annuities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Loss and loss expense reserves	757	762
Investment contract reserves: | Structured Settlement Annuity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Loss and loss expense reserves	$ 135	$ 136