PENSIONS AND OTHER POST RETIREMENT BENEFITS (Tables)

12 Months Ended

Dec. 31, 2020

PENSIONS AND OTHER POST RETIREMENT BENEFITS

Schedule of defined benefit obligations and funded status

			Pension Benefits				Other                   Post-Retirement                   Benefits
($ millions)			2020		2019		2020		2019
Change in benefit obligation
	Benefit obligation at beginning of year		7 708		6 730		631		557
	Current service costs		272		220		15		13
	Plan participants' contributions		17		16		—		—
	Benefits paid		(316	)	(293	)	(24	)	(24	)
	Interest costs		238		255		19		22
	Foreign exchange		1		(13	)	—		(1	)
	Settlements		5		5		—		—
	Actuarial remeasurement:
		Experience gain arising on plan liabilities	(26	)	(11	)	(6	)	(2	)
		Actuarial loss arising from changes in demographic assumptions	50		—		12		—
		Actuarial loss arising from changes in financial assumptions	733		799		43		66
Benefit obligation at end of year			8 682		7 708		690		631
Change in plan assets
	Fair value of plan assets at beginning of year		6 693		5 795		—		—
	Employer contributions		132		157		—		—
	Plan participants' contributions		17		16		—		—
	Benefits paid		(290	)	(269	)	—		—
	Foreign exchange		(1	)	(8	)	—		—
	Settlements		5		5		—		—
	Administrative costs		(2	)	(2	)	—		—
	Income on plan assets		203		218		—		—
	Actuarial remeasurement:
		Return on plan assets greater than discount rate	548		781		—		—
Fair value of plan assets at end of year			7 305		6 693		—		—
Net unfunded obligation			1 377		1 015		690		631

Schedule of defined benefit plan expenses

		Pension Benefits		Other                   Post-Retirement                   Benefits
($ millions)		2020	2019	2020	2019
Analysis of amount charged to earnings:
	Current service costs	272	220	15	13
	Interest costs	35	37	19	22
Defined benefit plans expense		307	257	34	35
Defined contribution plans expense		83	82	—	—
Total benefit plans expense charged to earnings		390	339	34	35

Components of defined benefit costs recognized in Other Comprehensive Income:

	Pension Benefits				Other                   Post-Retirement                   Benefits
($ millions)	2020		2019		2020		2019
Return on plan assets (excluding amounts included in net interest expense)	(548	)	(781	)	—		—
Experience gain arising on plan liabilities	(26	)	(11	)	(6	)	(2	)
Actuarial loss arising from changes in financial assumptions	733		799		43		66
Actuarial loss arising from changes in demographic assumptions	50		—		12		—
Actuarial loss recognized in other comprehensive income	209		7		49		64

Schedule of weighted average actuarial assumptions

	Pension Benefits		Other                   Post-Retirement                   Benefits
(%)	December 31 2020	December 31 2019	December 31 2020	December 31 2019
Discount rate	2.50	3.10	2.50	3.10
Rate of compensation increase(1)	3.00	3.00	3.00	3.00

(1) Rate of compensation increase is 2.5% from 2021 to 2023 and 3.0% thereafter.

Schedule of changes in assumed assumptions

		Pension Benefits
($ millions)		Increase		Decrease
1% change in discount rate
	Effect on the aggregate service and interest costs	(24	)	33
	Effect on the benefit obligations	(1 175	)	1 533

		Other                   Post-Retirement                   Benefits
($ millions)		Increase		Decrease
1% change in discount rate
	Effect on the benefit obligations	(86	)	108
1% change in health care cost
	Effect on the aggregate service and interest costs	1		(1	)
	Effect on the benefit obligations	38		(32	)

Schedule of weighted average pension plan asset allocations based on market value

(%)		2020	2019
Equities, comprised of:
	– Canada	11	12
	– United States	19	19
	– Foreign	20	19
		50	50
Fixed income, comprised of:
	– Canada	38	41
Real estate, comprised of:
	– Canada	12	9
Total		100	100