PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS (Tables)

12 Months Ended

Dec. 31, 2019

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	2019			2018			2019			2018
Change in projected benefit obligations:
Benefit obligation at beginning of year	$	3,786		$	4,150		$	215		$	224
Service cost	34			39			1			1
Interest cost	145			128			7			6
Actuarial changes in assumptions and experience	453			(249		)	12			(2		)
Benefits paid	(280		)	(278		)	(15		)	(14		)
Other	(41		)	(4		)	—			—
Benefit obligation at end of year	$	4,097		$	3,786		$	220		$	215
Change in plan assets:
Fair value of plan assets at beginning of year	$	3,005		$	3,307		$	—		$	—
Actual return on plan assets	464			(62		)	—			—
Employer contributions	2			42			—			—
Asset transfers	(43		)	(4		)	—			—
Benefits paid	(280		)	(278		)	—			—
Fair value of plan assets at end of year	$	3,148		$	3,005		$	—		$	—
Funded status at end of year	$	(949	)	$	(781	)	$	(220	)	$	(215	)

Net amounts recognized in the consolidated balance sheets at Dec 31:
Accrued and other current liabilities	$	(2	)	$	(2	)	$	(17	)	$	(19	)
Pension and other postretirement benefits - noncurrent	(947		)	(779		)	(203		)	(196		)
Net amount recognized	$	(949	)	$	(781	)	$	(220	)	$	(215	)
Pretax amounts recognized in accumulated other comprehensive loss at Dec 31:
Net loss (gain)	$	2,137		$	2,019		$	(60	)	$	(79	)
Prior service credit	(10		)	(11		)	—			—
Pretax balance in accumulated other comprehensive loss at end of year	$	2,127		$	2,008		$	(60	)	$	(79	)

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	2019		2018
In millions
Projected benefit obligations	$	4,097	$	3,786
Fair value of plan assets	$	3,148	$	3,005

Schedule of Net Benefit Costs

Net Periodic Benefit Cost for All Plans for the Year Ended Dec 31	Defined Benefit Pension Plans									Other Postretirement Benefit Plan
In millions	2019			2018			2017			2019			2018			2017
Net Periodic Benefit Cost:
Service cost	$	34		$	39		$	38		$	1		$	1		$	1
Interest cost	145			128			129			7			6			8
Expected return on plan assets	(210		)	(218		)	(221		)	—			—			—
Amortization of prior service credit	(1		)	(1		)	(1		)	—			—			—
Amortization of net (gain) loss	84			95			83			(8		)	(9		)	(6		)
Net periodic benefit cost	$	52		$	43		$	28		$	—		$	(2	)	$	3
Changes in plan assets and benefit obligations recognized in other comprehensive (income) loss:
Net (gain) loss	$	202		$	31		$	131		$	11		$	(2	)	$	(23	)
Amortization of prior service credit	1			1			1			—			—			—
Amortization of net gain (loss)	(84		)	(95		)	(83		)	8			9			6
Total recognized in other comprehensive (income) loss	$	119		$	(63	)	$	49		$	19		$	7		$	(17	)
Total recognized in net periodic benefit cost and other comprehensive (income) loss	$	171		$	(20	)	$	77		$	19		$	5		$	(14	)

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, 2019	Defined Benefit Pension Plans		Other Postretirement Benefit Plan
In millions
2020	$	277	$	17
2021	276		16
2022	274		17
2023	271		18
2024	268		18
2025 through 2029	1,264		78
Total	$	2,630	$	164

Schedule of Allocation of Plan Assets

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

Target Allocation for Plan Assets at Dec 31, 2019	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, 2019 and 2018:

Basis of Fair Value Measurements	Dec 31, 2019										Dec 31, 2018
In millions	Total			Level 1		Level 2			Level 3		Total		Level 1		Level 2		Level 3
Cash and cash equivalents	$	160		$	148	$	12		$	—	$	189	$	189	$	—	$	—
Equity securities:
U.S. equity securities	$	346		$	344	$	2		$	—	$	277	$	275	$	2	$	—
Non - U.S. equity securities	369			325		40			4		321		269		46		6
Total equity securities	$	715		$	669	$	42		$	4	$	598	$	544	$	48	$	6
Fixed income securities:
Debt - government-issued	$	812		$	7	$	805		$	—	$	812	$	8	$	804	$	—
Debt - corporate-issued	455			9		446			—		413		11		402		—
Debt - asset-backed	13			—		13			—		30		—		30		—
Total fixed income securities	$	1,280		$	16	$	1,264		$	—	$	1,255	$	19	$	1,236	$	—
Alternative investments:
Private market securities	$	5		$	—	$	—		$	5	$	—	$	—	$	—	$	—
Derivatives - asset position	—			—		—			—		12		—		12		—
Derivatives - liability position	(3		)	—		(3		)	—		—		—		—		—
Total alternative investments	$	2		$	—	$	(3	)	$	5	$	12	$	—	$	12	$	—
Other investments	$	2		$	5	$	(3	)	$	—	$	—	$	—	$	—	$	—
Subtotal	$	2,159		$	838	$	1,312		$	9	$	2,054	$	752	$	1,296	$	6
Investments measured at net asset value:
Hedge funds	$	266									$	287
Private market securities	389										335
Real estate	341										327
Total investments measured at net asset value	$	996									$	949
Items to reconcile to fair value of plan assets:
Pension trust receivables 1	$	—									$	2
Pension trust payables 2	(7		)								—
Total	$	3,148									$	3,005

1. Primarily receivables for investment securities sold.

2.

Primarily payables for investment securities purchased.

Defined Benefit Pension Plans [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 costs are provided below:

Pension Plan Assumptions	Benefit Obligations at Dec 31				Net Periodic Costs for the Year Ended
	2019		2018		2019		2018		2017
Discount rate	3.29	%	4.32	%	4.32	%	3.59	%	4.00	%
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	2019		2018
Accumulated benefit obligations	$	4,071	$	3,762
Fair value of plan assets	$	3,148	$	3,005

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, 2019 and 2018:

Fair Value Measurement of Level 3 Pension Plan Assets	Equity Securities			Alternative Investments			Total
In millions
Balance at Jan 1, 2018	$	7		$	—		$	7
Actual return on plan assets:
Relating to assets held at Dec 31, 2018	(1		)	—			(1		)
Balance at Dec 31, 2018	$	6		$	—		$	6
Actual return on plan assets:
Relating to assets held at Dec 31, 2019	—			(5		)	(5		)
Purchases, sales and settlements	(2		)	10			8
Balance at Dec 31, 2019	$	4		$	5		$	9

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 costs for the plan are provided in the following table:

Other Postretirement Benefit Plan Assumptions	Benefit Obligations at Dec 31				Net Periodic Costs for the Year Ended
	2019		2018		2019		2018		2017
Discount rate	3.17	%	4.23	%	4.23	%	3.51	%	3.88	%
Health care cost trend rate assumed for next year	6.25	%	6.50	%	6.50	%	6.75	%	7.00	%
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	2025		2025		2025		2025		2025