Debt - Other Outstanding Letters of Credit (Detail) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Line of Credit Facility [Line Items]
Other outstanding letters of credit	$ 259	$ 269
Committed Lines
Line of Credit Facility [Line Items]
Other outstanding letters of credit	29	54
Uncommitted Lines
Line of Credit Facility [Line Items]
Other outstanding letters of credit	$ 230	$ 215