Pension and Other Postretirement Benefits - Additional Information (Detail)				1 Months Ended	3 Months Ended						12 Months Ended
	Dec. 16, 2021 USD ($)	Nov. 23, 2021 USD ($)	Oct. 19, 2021 USD ($)	Dec. 31, 2020 USD ($) Employee	Dec. 31, 2021 USD ($) Employee Retiree	Sep. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($) Employee	Dec. 31, 2020 USD ($) Employee	Sep. 30, 2020 Employee	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($) Employee	Dec. 31, 2020 USD ($) Employee	Dec. 31, 2019 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Number of employees covered under defined benefit plans | Employee					14,000							14,000
Increase (decrease) to accrued other postretirement benefits liability												$ (106,000,000)	$ 74,000,000
Curtailment charge (gain)												17,000,000	(7,000,000)
Settlement charge												(994,000,000)	(44,000,000)
Increase (decrease) to accrued other pension benefits liability												(206,000,000)	$ 205,000,000
Number of employees affected the change in defined benefit plans | Employee				11,280					11,280				11,280
Fair value of plan assets				$ 5,348,000,000	$ 4,264,000,000				$ 5,348,000,000			$ 4,264,000,000	$ 5,348,000,000
Health care cost trend rate assumed for next year				5.50%	5.50%				5.50%			5.50%	5.50%	5.50%
Cash contribution to pension plans												$ 579,000,000	$ 343,000,000	$ 173,000,000
Company's contribution												500,000,000
Deferral of pension contributions, CARES Act				$ 200,000,000					$ 200,000,000				200,000,000
Expenses related to saving and investment plans												72,000,000	73,000,000	68,000,000
Expenses related to member-funded pension plan				10,000,000	$ 17,000,000				10,000,000			$ 17,000,000	10,000,000
Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected long term rate of return on plan assets											4.94%
Expected minimum required cash contribution to pension plans, next year											$ 80,000,000
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Weighted average discount rate yield curve												12 years
United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan obligations				4,695,000,000	2,712,000,000				4,695,000,000			$ 2,712,000,000	4,695,000,000
Fair value of plan assets				3,676,000,000	2,681,000,000				3,676,000,000			2,681,000,000	3,676,000,000
Funded status				(1,019,000,000)	$ (31,000,000)				$ (1,019,000,000)			(31,000,000)	(1,019,000,000)
Cash contribution to pension plans				$ 250,000,000
United States [Member] | Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected minimum required cash contribution to pension plans, next year											$ 65,000,000
Warrick Rolling Mill [Member] | Held for Sale [Member]
Defined Benefit Plan Disclosure [Line Items]
Sale transaction value of waste processing								$ 670,000,000
Assumption of other postretirement benefit liabilities								$ 69,000,000
Number of employees | Employee								1,150
Action# 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Curtailment charge (gain)													(1,000,000)
Increase (decrease) to accrued other pension benefits liability													$ 18,000,000
Collective bargaining agreement term													6 years
Number of employees affected the change in defined benefit plans | Employee				20					20				20
Percentage of employers contribution in defined benefit plans													12.00%
Action# 1 [Member] | Warrick Rolling Mill [Member] | Held for Sale [Member]
Defined Benefit Plan Disclosure [Line Items]
Sale transaction value of waste processing								$ 670,000,000
Assumption of other postretirement benefit liabilities							$ 69,000,000
Number of employees | Employee								1,150
Increase (decrease) to accrued other postretirement benefits liability								$ (40,000,000)
Remeasurement to accrued other postretirement benefits liability												69,000,000
Curtailment charge (gain)								(17,000,000)
Settlement charge								$ 26,000,000
Action# 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement charge												(39,000,000)
Increase (decrease) to accrued other pension benefits liability												$ (90,000,000)
Number of employees affected the change in defined benefit plans | Employee					120							120
Action# 2 [Member] | Warrick Rolling Mill [Member] | Held for Sale [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement charge							39,000,000
Increase (decrease) to accrued other pension benefits liability							$ (90,000,000)
Action# 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement charge						$ 7,000,000						$ (7,000,000)
Increase (decrease) to accrued other pension benefits liability						7,000,000						$ 7,000,000
Number of employees affected the change in defined benefit plans | Employee					20							20
Action# 4 [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement charge						1,000,000						$ (1,000,000)
Increase (decrease) to accrued other pension benefits liability						$ (38,000,000)						$ (38,000,000)
Number of employees affected the change in defined benefit plans | Employee					20							20
Action# 5 [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement charge												$ (63,000,000)
Number of retirees | Retiree					800
Plan obligations			$ 55,000,000
Plan assets			$ 55,000,000
Number of employees affected the change in defined benefit plans | Employee					800							800
Action# 5 [Member] | Restructuring And Other Charges [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement charge					$ 63,000,000
Action# 6 [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement charge												$ (848,000,000)
Increase (decrease) to accrued other pension benefits liability					$ 84,000,000							$ (84,000,000)
Number of retirees | Retiree					14,000
Plan obligations	$ 1,540,000,000	$ 1,540,000,000
Plan assets	$ 1,540,000,000	$ 1,540,000,000
Number of employees affected the change in defined benefit plans | Employee					14,000							14,000
Action# 6 [Member] | Restructuring And Other Charges [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement charge					$ 848,000,000
Action# 7 [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement charge												$ (10,000,000)
Increase (decrease) to accrued other pension benefits liability					$ 1,000,000							$ (1,000,000)
Number of employees affected the change in defined benefit plans | Employee					60							60
Action# 7 [Member] | Restructuring And Other Charges [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement charge					$ 10,000,000
Action# 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Curtailment charge (gain)													$ (2,000,000)
Increase (decrease) to accrued other pension benefits liability													$ 28,000,000
Number of employees affected the change in defined benefit plans | Employee				430					430				430
Percentage of employers contribution in defined benefit plans													12.00%
Action# 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Number of employees reduced | Employee										685
Action# 4 [Member]
Defined Benefit Plan Disclosure [Line Items]
Increase (decrease) to accrued other postretirement benefits liability													$ 74,000,000
Number of employees affected the change in defined benefit plans | Employee				8,600					8,600				8,600
Action# 5 [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement charge													$ (44,000,000)
Increase (decrease) to accrued other pension benefits liability													(2,000,000)
Plan assets													$ 33,000,000
Number of employees affected the change in defined benefit plans | Employee				430					430				430
Lump sum settlements in plan obligations on pension and other postretirement benefits													$ 35,000,000
Action# 6 [Member]
Defined Benefit Plan Disclosure [Line Items]
Curtailment charge (gain)									$ (5,000,000)				(5,000,000)
Increase (decrease) to accrued other pension benefits liability													$ 5,000,000
Number of employees affected the change in defined benefit plans | Employee				900					900				900
Number of employees on rolling operations | Employee				1,170					1,170				1,170
Target Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Company's contribution												$ 9,000,000
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Number of employees covered under defined benefit plans | Employee					37,000							37,000
Curtailment charge (gain)													$ (9,000,000)	(38,000,000)
Settlement charge												$ 968,000,000	51,000,000	$ 73,000,000
Plan obligations				$ 6,904,000,000	$ 4,594,000,000				$ 6,904,000,000			4,594,000,000	6,904,000,000
Funded status				1,548,000,000	$ 288,000,000				1,548,000,000			$ 288,000,000	$ 1,548,000,000
Expected long term rate of return on plan assets												5.66%	6.28%	6.59%
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Number of employees covered under defined benefit plans | Employee					24,000							24,000
Curtailment charge (gain)												$ 17,000,000	$ 2,000,000
Settlement charge												26,000,000		$ 8,000,000
Funded status				$ 892,000,000	$ 710,000,000				$ 892,000,000			$ 710,000,000	$ 892,000,000