Employee Benefit Plans (Summary of Changes in Pension and Other Postretirement Benefit Plans) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Amounts recognized in the Consolidated Balance Sheets at December 31:
Noncurrent pension and other postretirement benefit assets	$ 1,779	$ 1,479
Noncurrent assets held for sale		18,831
Noncurrent liabilities held for sale	0	(7,544)
Pension Benefits
Changes in benefit obligation:
Benefit obligation at beginning of year	8,066	10,890	$ 8,066
Service cost	$ 96	$ 142	$ 170
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Interest cost	$ 442	$ 333	$ 317
Benefits paid	(493)	(511)
Actuarial (gain) loss during the year	322	(2,716)
Plan amendments	2
Sale of Hope		(64)
Settlements and curtailments	(4)	(8)
Benefit obligation at end of year	8,431	8,066	10,890	$ 8,066
Changes in fair value of plan assets:
Fair value of plan assets at beginning of year	8,694	11,945
Actual return gain (loss) on plan assets	882	(2,556)
Employer contributions	8	9
Benefits paid	(493)	(511)
Sale of Hope		(188)
Settlements	(4)	(5)
Fair value of plan assets at end of year	9,087	8,694	11,945
Funded status at end of year	656	628
Amounts recognized in the Consolidated Balance Sheets at December 31:
Noncurrent pension and other postretirement benefit assets	647	580
Noncurrent assets held for sale	308	295
Other current liabilities	(27)	(12)
Noncurrent pension and other postretirement benefit liabilities	(237)	(196)
Noncurrent liabilities held for sale	(35)	(39)
Net amount recognized	$ 656	$ 628
Significant assumptions used to determine benefit obligations as of December 31:
Weighted average rate of increase for compensation	4.28%	4.38%
Pension Benefits | Minimum
Significant assumptions used to determine benefit obligations as of December 31:
Discount rate	5.37%	5.65%
Crediting interest rate for cash balance and similar plans	4.12%	4.40%
Pension Benefits | Maximum
Significant assumptions used to determine benefit obligations as of December 31:
Discount rate	5.47%	5.75%
Crediting interest rate for cash balance and similar plans	4.22%	4.50%
Other Postretirement Benefits
Changes in benefit obligation:
Benefit obligation at beginning of year	$ 1,127	$ 1,537
Service cost	$ 14	$ 22	$ 25
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Interest cost	$ 61	$ 45	$ 46
Benefits paid	(94)	(97)
Actuarial (gain) loss during the year	1	(361)
Sale of Hope		(19)
Benefit obligation at end of year	1,109	1,127	1,537
Changes in fair value of plan assets:
Fair value of plan assets at beginning of year	1,845	2,323
Actual return gain (loss) on plan assets	277	(416)
Benefits paid	(60)	(62)
Fair value of plan assets at end of year	2,062	1,845	$ 2,323
Funded status at end of year	953	718
Amounts recognized in the Consolidated Balance Sheets at December 31:
Noncurrent pension and other postretirement benefit assets	1,132	899
Noncurrent assets held for sale	13	11
Other current liabilities	(13)	(13)
Noncurrent pension and other postretirement benefit liabilities	(179)	(179)
Net amount recognized	$ 953	$ 718
Other Postretirement Benefits | Minimum
Significant assumptions used to determine benefit obligations as of December 31:
Discount rate	5.40%	5.69%
Other Postretirement Benefits | Maximum
Significant assumptions used to determine benefit obligations as of December 31:
Discount rate	5.42%	5.70%