Reserve for Known and Incurred but Not Reported Claims - Reconciliation of the Net Incurred and Paid Claims Development Tables to the Liability for Claims and Claim Adjustment Expense (Detail) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Shortduration Insurance Contracts Liability For Unpaid Claims And Allocated Claim Adjustment Expense Net [Abstract]
Liability for unpaid claims and claim adjustment expenses, net of reinsurance: Specialty insurance	$ 72
Unallocated claims adjustment expenses: Specialty insurance	2
Title insurance	1,210	$ 1,090
Total loss reserves, amount	$ 1,284	$ 1,178	$ 1,063	$ 1,042

Reserve for Known and Incurred but Not Reported Claims - Reconciliation of the Net Incurred and Paid Claims Development Tables to the Liability for Claims and Claim Adjustment Expense (Detail) - USD ($)
$ in Millions

Dec. 31, 2021

Dec. 31, 2020

Dec. 31, 2019

Dec. 31, 2018

Shortduration Insurance Contracts Liability For Unpaid Claims And Allocated Claim Adjustment Expense Net [Abstract]

Liability for unpaid claims and claim adjustment expenses, net of reinsurance: Specialty insurance

$ 72

Unallocated claims adjustment expenses: Specialty insurance

Title insurance

1,210

$ 1,090

Total loss reserves, amount

$ 1,284

$ 1,178

$ 1,063

$ 1,042