Reserve for Known and Incurred but Not Reported Claims (Summary of Loss Reserves) (Detail) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Insurance [Abstract]
Known title claims, amount	$ 67	$ 64
IBNR title claims, amount	1,143	1,026
Total title claims, amount	1,210	1,090
Non-title claims, amount	74	88
Total loss reserves, amount	$ 1,284	$ 1,178	$ 1,063	$ 1,042
Known title claims, percent	5.20%	5.40%
IBNR title claims, percent	89.00%	87.10%
Total title claims, percent	94.20%	92.50%
Non-title claims, percent	5.80%	7.50%
Total loss reserves	100.00%	100.00%