PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS (Tables)

12 Months Ended

Dec. 31, 2023

Defined Benefit Plan Disclosure [Line Items]

Changes in Projected Benefit Obligations, Fair Value of Plan Assets, and Funded Status of Plan

Summarized information on the Corporation's pension and other postretirement benefit plans is as follows:

Change in Projected Benefit Obligations, Plan Assets and Funded Status for All Plans	Defined Benefit Pension Plans				Other Postretirement Benefit Plan
In millions	2023		2022		2023		2022
Change in projected benefit obligations:
Benefit obligations at beginning of year	$	2,860	$	3,940	$	128	$	174
Service cost	32		37		—		1
Interest cost	147		91		7		3
Actuarial changes in assumptions and experience	55		(826)		6		(48)
Benefits paid	(246)		(265)		(8)		(2)
Termination of benefits/settlement 1	(211)		—		—		—
Acquisition/divestiture/other 2	(4)		(117)		—		—
Benefit obligations at end of year	$	2,633	$	2,860	$	133	$	128
Change in plan assets:
Fair value of plan assets at beginning of year	$	2,679	$	3,611	$	—	$	—
Actual return on plan assets	146		(556)		—		—
Employer contributions	2		3		—		—
Asset transfers	(5)		(8)		—		—
Benefits paid	(246)		(265)		—		—
Settlement 3	(211)		—		—		—
Other 4	5		(106)		—		—
Fair value of plan assets at end of year	$	2,370	$	2,679	$	—	$	—
Funded status at end of year	$	(263)	$	(181)	$	(133)	$	(128)

Net amounts recognized in the consolidated balance sheets at Dec 31:
Deferred charges and other assets	$	10	$	—	$	—	$	—
Accrued and other current liabilities	(2)		(2)		(12)		(12)
Pension and other postretirement benefits - noncurrent	(271)		(179)		(121)		(116)
Net amount recognized	$	(263)	$	(181)	$	(133)	$	(128)
Pretax amounts recognized in accumulated other comprehensive loss at Dec 31:
Net loss (gain)	$	1,752	$	1,852	$	(102)	$	(124)

1.The 2023 impact primarily relates to the transfer of certain pension benefit obligations through the purchase of annuity contracts from an insurance company, triggering settlement accounting.

2.The 2022 impact primarily relates to the transfer of certain pension benefit obligations through the purchase of annuity contracts from an insurance company.

3.The 2023 impact primarily relates to the purchase of an annuity contract associated with the transfer of certain pension benefit obligations to an insurance company, triggering settlement accounting.

4.The 2022 impact primarily relates to the purchase of an annuity contract associated with the transfer of benefit obligations to an insurance company.

Schedule of Net Benefit Costs

Net Periodic Benefit Cost (Credit) for All Plans for the Year Ended Dec 31	Defined Benefit Pension Plans						Other Postretirement Benefit Plan
In millions	2023		2022		2021		2023		2022		2021
Net Periodic Benefit Cost (Credit):
Service cost	$	32	$	37	$	26	$	—	$	1	$	1
Interest cost	147		91		80		7		3		3
Expected return on plan assets	(204)		(226)		(219)		—		—		—
Amortization of prior service credit	—		(1)		(1)		—		—		—
Amortization of net (gain) loss	60		108		116		(15)		(9)		(4)
Curtailment and settlement (gain) loss 1	149		—		(7)		—		—		—
Net periodic benefit cost (credit)	$	184	$	9	$	(5)	$	(8)	$	(5)	$	—
Changes in plan assets and benefit obligations recognized in other comprehensive (income) loss:
Net (gain) loss	$	109	$	(47)	$	(144)	$	7	$	(49)	$	(36)
Amortization of prior service credit	—		1		1		—		—		—
Amortization of net gain (loss)	(60)		(108)		(116)		15		9		4
Curtailment and settlement gain (loss) 1	(149)		—		7		—		—		—
Total recognized in other comprehensive (income) loss	$	(100)	$	(154)	$	(252)	$	22	$	(40)	$	(32)
Total recognized in net periodic benefit cost and other comprehensive (income) loss	$	84	$	(145)	$	(257)	$	14	$	(45)	$	(32)

1.The 2023 impact relates to the settlement of certain pension benefit obligations through the purchase of a nonparticipating group annuity contract from an insurer. The 2021 impact relates to the freeze of pensionable compensation and credited service amounts for employees that participate in the UCC Plans.

Schedule of Expected Benefit Payments

The estimated future benefit payments, reflecting expected future service, as appropriate, are presented in the following table:

Estimated Future Benefit Payments at Dec 31, 2023	Defined Benefit Pension Plans		Other Postretirement Benefit Plan
In millions
2024	$	238	$	13
2025	213		13
2026	210		13
2027	207		12
2028	203		12
2029 through 2033	945		51
Total	$	2,016	$	114

Pension Plan [Member]

Defined Benefit Plan Disclosure [Line Items]

Schedule of Assumptions Used

The weighted-average assumptions used to determine pension plan obligations and net periodic benefit cost are provided below:

Pension Plan Assumptions	Benefit Obligations at Dec 31				Net Periodic Benefit Cost for the Year Ended
	2023		2022		2023		2022		2021
Discount rate	5.25	%	5.60	%	5.72	%	2.94	%	2.86	%
Interest crediting rate for applicable benefits	4.50	%	4.50	%	4.50	%	4.50	%	4.50	%
Rate of compensation increase	4.25	%	4.25	%	4.25	%	4.25	%	4.25	%
Expected return on plan assets					6.80	%	6.80	%	6.80	%

Schedule of Accumulated Benefit Obligations in Excess of Fair Value of Plan Assets

Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets at Dec 31
In millions	2023		2022
Accumulated benefit obligations	$	2,593	$	2,859
Fair value of plan assets	$	2,320	$	2,679

Schedule of Projected Benefit Obligations in Excess of Fair Value of Plan Assets

Pension Plans with Projected Benefit Obligations in Excess of Plan Assets at Dec 31	2023		2022
In millions
Projected benefit obligations	$	2,593	$	2,860
Fair value of plan assets	$	2,320	$	2,679

Schedule of Allocation of Plan Assets

The weighted-average target allocation for plan assets of the Corporation's pension plan is summarized as follows:

Target Allocation for Plan Assets at Dec 31, 2023	Target Allocation
Asset Category
Equity securities	23	%
Fixed income securities	45
Alternative investments	27
Other	5
Total	100	%

Schedule of Defined Benefit Plans Disclosures

The following table summarizes the bases used to measure the Corporation’s pension plan assets at fair value for the years ended December 31, 2023 and 2022:

Basis of Fair Value Measurements	Dec 31, 2023								Dec 31, 2022
In millions	Total		Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3
Cash and cash equivalents	$	203	$	188	$	15	$	—	$	224	$	172	$	52	$	—
Equity securities:
U.S. equity securities	$	239	$	238	$	1	$	—	$	288	$	288	$	—	$	—
Non - U.S. equity securities	250		238		11		1		255		244		11		—
Total equity securities	$	489	$	476	$	12	$	1	$	543	$	532	$	11	$	—
Fixed income securities:
Debt - government-issued	$	720	$	—	$	720	$	—	$	665	$	1	$	664	$	—
Debt - corporate-issued	265		1		264		—		442		1		441		—
Debt - asset-backed	37		—		37		—		20		—		20		—
Total fixed income securities	$	1,022	$	1	$	1,021	$	—	$	1,127	$	2	$	1,125	$	—
Alternative investments:
Private markets	$	—	$	—	$	—	$	—	$	2	$	—	$	—	$	2
Derivatives - asset position	7		—		7		—		5		—		5		—
Derivatives - liability position	(13)		—		(13)		—		(16)		—		(16)		—
Total alternative investments	$	(6)	$	—	$	(6)	$	—	$	(9)	$	—	$	(11)	$	2
Other investments	$	1	$	1	$	—	$	—	$	3	$	2	$	1	$	—
Subtotal	$	1,709	$	666	$	1,042	$	1	$	1,888	$	708	$	1,178	$	2
Investments measured at net asset value:
Hedge funds	$	125							$	142
Private markets	344								411
Real estate	199								240
Total investments measured at net asset value	$	668							$	793
Items to reconcile to fair value of plan assets:
Pension trust receivables 1	$	7							$	4
Pension trust payables 2	(14)								(6)
Total	$	2,370							$	2,679

1.Primarily receivables for investment securities sold.

2.Primarily payables for investment securities purchased.

Schedule of Effect of Significant Unobservable Inputs, Changes in Plan Assets

The following table summarizes the changes in fair value of Level 3 pension plan assets for the years ended December 31, 2023 and 2022:

Fair Value Measurement of Level 3 Pension Plan Assets	Equity Securities		Alternative Investments		Total
In millions
Balance at Jan 1, 2022	$	1	$	2	$	3
Actual return on plan assets:
Relating to assets held at Dec 31, 2022	(1)		(2)		(3)
Purchases, sales and settlements	—		2		2
Balance at Dec 31, 2022	$	—	$	2	$	2
Actual return on plan assets:
Relating to assets held at Dec 31, 2023	1		(2)		(1)
Balance at Dec 31, 2023	$	1	$	—	$	1

Other Postretirement Benefits Plan [Member]

Defined Benefit Plan Disclosure [Line Items]

Schedule of Assumptions Used

The weighted-average assumptions used to determine other postretirement benefit plan obligations and net periodic benefit cost for the plan are provided in the following table:

Other Postretirement Benefit Plan Assumptions	Benefit Obligations at Dec 31				Net Periodic Benefit Cost for the Year Ended
	2023		2022		2023		2022		2021
Discount rate	5.20	%	5.56	%	5.56	%	2.84	%	2.34	%
Health care cost trend rate assumed for next year	6.50	%	6.57	%	6.57	%	6.50	%	6.75	%
Rate to which the cost trend rate is assumed to decline (the ultimate health care cost trend rate)	5.00	%	5.00	%	5.00	%	5.00	%	5.00	%
Year that the rate reaches the ultimate health care cost trend rate	2033		2033		2033		2028		2028