Employee Benefit Plans - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($) Employee	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Compensation Related Costs Disclosure [Line Items]
Expenses for defined-contribution plans	$ 51	$ 70	$ 68
Net periodic benefit income (cost)	3	$ 2	$ 3
Defined benefit plan, expected future benefit payments in year five	$ 34
Expected years of defined benefit plans	5 years
Expected future benefit amounts to pay, total	$ 325
United States [Member]
Compensation Related Costs Disclosure [Line Items]
Number of U.S. employees participate in defined benefit health care plans | Employee	21
Number of U.S retirees and spouses participate in defined benefit health care plans | Employee	1,594