Contingencies and Commitments - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($) Project	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Loss Contingencies [Line Items]
Environmental remediation reserve balance, current	$ 44	$ 29
Liabilities incurred	21	7	$ 73
Payments related to remediation expenses applied against the reserve	23	19	17
Reversals of previously recorded liabilities	17		1
Active or future remediation for significant sites	247	259
Accrued environmental reserves	$ 309	322	335	$ 280
Massena, New York [Member] | Minimum [Member]
Loss Contingencies [Line Items]
Environmental remediation work completion period	4 years
Massena, New York [Member] | Maximum [Member]
Loss Contingencies [Line Items]
Environmental remediation work completion period	8 years
Other Sites [Member]
Loss Contingencies [Line Items]
Number of remediation projects | Project	35
Accrued environmental reserves	$ 62	63
Restructuring And Other Charges [Member]
Loss Contingencies [Line Items]
Additional accrual		1
Ongoing Remediation Work [Member]
Loss Contingencies [Line Items]
Liabilities incurred		$ 7
Closure of Point Comfort Alumina Refinery [Member]
Loss Contingencies [Line Items]
Liabilities incurred			$ 73
Closed Suriname Site [Member]
Loss Contingencies [Line Items]
Reversals of previously recorded liabilities	7
Closed Site in Brazil [Member]
Loss Contingencies [Line Items]
Reversals of previously recorded liabilities	5
Closed Tennessee Site [Member]
Loss Contingencies [Line Items]
Reversals of previously recorded liabilities	$ 5