Pension and Other Postretirement Benefits - Additional Information (Detail) $ in Millions		3 Months Ended
	Apr. 01, 2021 USD ($)	Mar. 31, 2021 USD ($) Employee	Mar. 31, 2020 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Curtailment gain			$ 3
Minimum required cash contribution to pension plans		$ 135
United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Minimum required cash contribution to pension plans		49
Non-U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Minimum required cash contribution to pension plans		14
Subsequent Event [Member]
Defined Benefit Plan Disclosure [Line Items]
Company's contribution	$ 500
Warrick Rolling Mill | Held for Sale
Defined Benefit Plan Disclosure [Line Items]
Sale transaction value of waste processing		670
Assumption of other postretirement benefit liabilities		$ 72
Number of employees | Employee		1,150
Action# 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Decrease to accrued other postretirement benefits liability		$ 112
Curtailment gain		17
Settlement charge		26
Action# 1 [Member] | Warrick Rolling Mill | Held for Sale
Defined Benefit Plan Disclosure [Line Items]
Sale transaction value of waste processing		670
Assumption of other postretirement benefit liabilities		$ 72
Number of employees | Employee		1,150
Decrease to accrued other postretirement benefits liability		$ 40
Remeasurement to accrued other postretirement benefits liability		72
Curtailment gain		17
Settlement charge		$ 26