XML 175 R152.htm IDEA: XBRL DOCUMENT v3.25.0.1
PENSION AND OTHER POSTRETIREMENT BENEFITS - Plan Assets (Details) - CAD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Change in plan assets    
Fair value of plan assets at beginning of year $ 61  
Fair value of plan assets at end of year $ 77 $ 61
Canada | Equity securities    
Pension and Other Postretirement Benefit Disclosures    
Allocation of plan assets (as a percent) 46.20%  
Plan asset allocations 39.10% 41.40%
Canada | Fixed income securities    
Pension and Other Postretirement Benefit Disclosures    
Allocation of plan assets (as a percent) 23.00%  
Plan asset allocations 31.60% 29.60%
Canada | Alternatives    
Pension and Other Postretirement Benefit Disclosures    
Allocation of plan assets (as a percent) 30.80%  
Plan asset allocations 29.30% 29.00%
Canada | Pension    
Change in plan assets    
Fair value of plan assets at beginning of year $ 4,528 $ 4,234
Fair value of plan assets at end of year 5,000 4,528
Canada | Pension | Level 1    
Change in plan assets    
Fair value of plan assets at beginning of year 227  
Fair value of plan assets at end of year 335 227
Canada | Pension | Level 2    
Change in plan assets    
Fair value of plan assets at beginning of year 3,011  
Fair value of plan assets at end of year 3,201 3,011
Canada | Pension | Level 3    
Change in plan assets    
Fair value of plan assets at beginning of year 1,290 1,291
Unrealized and realized gains 104 (41)
Purchases and settlements, net 70 40
Fair value of plan assets at end of year 1,464 1,290
Canada | Pension | Alternatives    
Change in plan assets    
Fair value of plan assets at beginning of year 1,290  
Fair value of plan assets at end of year 1,464 1,290
Canada | Pension | Alternatives | Level 1    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
Canada | Pension | Alternatives | Level 2    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
Canada | Pension | Alternatives | Level 3    
Change in plan assets    
Fair value of plan assets at beginning of year 1,290  
Fair value of plan assets at end of year 1,464 1,290
Canada | Pension | Cash and Cash Equivalents    
Change in plan assets    
Fair value of plan assets at beginning of year 227  
Fair value of plan assets at end of year 201 227
Canada | Pension | Cash and Cash Equivalents | Level 1    
Change in plan assets    
Fair value of plan assets at beginning of year 227  
Fair value of plan assets at end of year 201 227
Canada | Pension | Cash and Cash Equivalents | Level 2    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
Canada | Pension | Cash and Cash Equivalents | Level 3    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
Canada | Pension | Equity Securities, Global    
Change in plan assets    
Fair value of plan assets at beginning of year 1,871  
Fair value of plan assets at end of year 1,951 1,871
Canada | Pension | Equity Securities, Global | Level 1    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 134 0
Canada | Pension | Equity Securities, Global | Level 2    
Change in plan assets    
Fair value of plan assets at beginning of year 1,871  
Fair value of plan assets at end of year 1,817 1,871
Canada | Pension | Equity Securities, Global | Level 3    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
Canada | Pension | Equity Securities, Global    
Change in plan assets    
Fair value of plan assets at beginning of year 3  
Fair value of plan assets at end of year 3 3
Canada | Pension | Equity Securities, Global | Level 1    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
Canada | Pension | Equity Securities, Global | Level 2    
Change in plan assets    
Fair value of plan assets at beginning of year 3  
Fair value of plan assets at end of year 3 3
Canada | Pension | Equity Securities, Global | Level 3    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
Canada | Pension | Government    
Change in plan assets    
Fair value of plan assets at beginning of year 446  
Fair value of plan assets at end of year 543 446
Canada | Pension | Government | Level 1    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
Canada | Pension | Government | Level 2    
Change in plan assets    
Fair value of plan assets at beginning of year 446  
Fair value of plan assets at end of year 543 446
Canada | Pension | Government | Level 3    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
Canada | Pension | Corporate    
Change in plan assets    
Fair value of plan assets at beginning of year 667  
Fair value of plan assets at end of year 838 667
Canada | Pension | Corporate | Level 1    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
Canada | Pension | Corporate | Level 2    
Change in plan assets    
Fair value of plan assets at beginning of year 667  
Fair value of plan assets at end of year 838 667
Canada | Pension | Corporate | Level 3    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
Canada | Pension | Foreign exchange contracts    
Change in plan assets    
Fair value of plan assets at beginning of year 24  
Fair value of plan assets at end of year   24
Canada | Pension | Foreign exchange contracts | Level 1    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year   0
Canada | Pension | Foreign exchange contracts | Level 2    
Change in plan assets    
Fair value of plan assets at beginning of year 24  
Fair value of plan assets at end of year   24
Canada | Pension | Foreign exchange contracts | Level 3    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year   0
Canada | OPEB    
Change in plan assets    
Fair value of plan assets at beginning of year 0 0
Fair value of plan assets at end of year $ 0 $ 0
US | Equity securities    
Pension and Other Postretirement Benefit Disclosures    
Allocation of plan assets (as a percent) 43.40%  
Plan asset allocations 44.80% 39.50%
US | Fixed income securities    
Pension and Other Postretirement Benefit Disclosures    
Allocation of plan assets (as a percent) 23.20%  
Plan asset allocations 33.00% 19.40%
US | Alternatives    
Pension and Other Postretirement Benefit Disclosures    
Allocation of plan assets (as a percent) 33.40%  
Plan asset allocations 22.20% 41.10%
US | Pension    
Change in plan assets    
Fair value of plan assets at beginning of year $ 1,052 $ 1,080
Fair value of plan assets at end of year 2,194 1,052
US | Pension | Level 1    
Change in plan assets    
Fair value of plan assets at beginning of year 8  
Fair value of plan assets at end of year 84 8
US | Pension | Level 2    
Change in plan assets    
Fair value of plan assets at beginning of year 611  
Fair value of plan assets at end of year 1,622 611
US | Pension | Level 3    
Change in plan assets    
Fair value of plan assets at beginning of year 433 445
Unrealized and realized gains 63 (12)
Purchases and settlements, net (8) 0
Fair value of plan assets at end of year 488 433
US | Pension | Alternatives    
Change in plan assets    
Fair value of plan assets at beginning of year 433  
Fair value of plan assets at end of year 488 433
US | Pension | Alternatives | Level 1    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
US | Pension | Alternatives | Level 2    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
US | Pension | Alternatives | Level 3    
Change in plan assets    
Fair value of plan assets at beginning of year 433  
Fair value of plan assets at end of year 488 433
US | Pension | Cash and Cash Equivalents    
Change in plan assets    
Fair value of plan assets at beginning of year 8  
Fair value of plan assets at end of year 57 8
US | Pension | Cash and Cash Equivalents | Level 1    
Change in plan assets    
Fair value of plan assets at beginning of year 8  
Fair value of plan assets at end of year 57 8
US | Pension | Cash and Cash Equivalents | Level 2    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
US | Pension | Cash and Cash Equivalents | Level 3    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
US | Pension | Equity Securities, Global    
Change in plan assets    
Fair value of plan assets at beginning of year 416  
Fair value of plan assets at end of year 981 416
US | Pension | Equity Securities, Global | Level 1    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 27 0
US | Pension | Equity Securities, Global | Level 2    
Change in plan assets    
Fair value of plan assets at beginning of year 416  
Fair value of plan assets at end of year 954 416
US | Pension | Equity Securities, Global | Level 3    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
US | Pension | Equity Securities, Global    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
US | Pension | Equity Securities, Global | Level 1    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
US | Pension | Equity Securities, Global | Level 2    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
US | Pension | Equity Securities, Global | Level 3    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
US | Pension | Government    
Change in plan assets    
Fair value of plan assets at beginning of year 46  
Fair value of plan assets at end of year 194 46
US | Pension | Government | Level 1    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
US | Pension | Government | Level 2    
Change in plan assets    
Fair value of plan assets at beginning of year 46  
Fair value of plan assets at end of year 194 46
US | Pension | Government | Level 3    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
US | Pension | Corporate    
Change in plan assets    
Fair value of plan assets at beginning of year 149  
Fair value of plan assets at end of year 474 149
US | Pension | Corporate | Level 1    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
US | Pension | Corporate | Level 2    
Change in plan assets    
Fair value of plan assets at beginning of year 149  
Fair value of plan assets at end of year 474 149
US | Pension | Corporate | Level 3    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
US | Pension | Foreign exchange contracts    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year   0
US | Pension | Foreign exchange contracts | Level 1    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year   0
US | Pension | Foreign exchange contracts | Level 2    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year   0
US | Pension | Foreign exchange contracts | Level 3    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year   0
US | OPEB    
Change in plan assets    
Fair value of plan assets at beginning of year 187 185
Fair value of plan assets at end of year 278 187
US | OPEB | Fair Value    
Change in plan assets    
Fair value of plan assets at beginning of year 187  
Fair value of plan assets at end of year 278 187
US | OPEB | Level 1 | Fair Value    
Change in plan assets    
Fair value of plan assets at beginning of year 45  
Fair value of plan assets at end of year 75 45
US | OPEB | Level 2 | Fair Value    
Change in plan assets    
Fair value of plan assets at beginning of year 113  
Fair value of plan assets at end of year 170 113
US | OPEB | Level 3    
Change in plan assets    
Fair value of plan assets at beginning of year 29 28
Unrealized and realized gains 5 1
Purchases and settlements, net (1) 0
Fair value of plan assets at end of year 33 29
US | OPEB | Level 3 | Fair Value    
Change in plan assets    
Fair value of plan assets at beginning of year 29  
Fair value of plan assets at end of year 33 29
US | OPEB | Alternatives | Fair Value    
Change in plan assets    
Fair value of plan assets at beginning of year 29  
Fair value of plan assets at end of year 33 29
US | OPEB | Alternatives | Level 1 | Fair Value    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
US | OPEB | Alternatives | Level 2 | Fair Value    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
US | OPEB | Alternatives | Level 3 | Fair Value    
Change in plan assets    
Fair value of plan assets at beginning of year 29  
Fair value of plan assets at end of year 33 29
US | OPEB | Cash and Cash Equivalents | Fair Value    
Change in plan assets    
Fair value of plan assets at beginning of year 3  
Fair value of plan assets at end of year 4 3
US | OPEB | Cash and Cash Equivalents | Level 1 | Fair Value    
Change in plan assets    
Fair value of plan assets at beginning of year 3  
Fair value of plan assets at end of year 4 3
US | OPEB | Cash and Cash Equivalents | Level 2 | Fair Value    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
US | OPEB | Cash and Cash Equivalents | Level 3 | Fair Value    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
US | OPEB | Equity Securities, US    
Change in plan assets    
Fair value of plan assets at beginning of year 36  
Fair value of plan assets at end of year 52 36
US | OPEB | Equity Securities, US | Level 1    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
US | OPEB | Equity Securities, US | Level 2    
Change in plan assets    
Fair value of plan assets at beginning of year 36  
Fair value of plan assets at end of year 52 36
US | OPEB | Equity Securities, US | Level 3    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
US | OPEB | Equity Securities, Global    
Change in plan assets    
Fair value of plan assets at beginning of year 62  
Fair value of plan assets at end of year 93 62
US | OPEB | Equity Securities, Global | Level 1    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
US | OPEB | Equity Securities, Global | Level 2    
Change in plan assets    
Fair value of plan assets at beginning of year 62  
Fair value of plan assets at end of year 93 62
US | OPEB | Equity Securities, Global | Level 3    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
US | OPEB | Government | Fair Value    
Change in plan assets    
Fair value of plan assets at beginning of year 45  
Fair value of plan assets at end of year 77 45
US | OPEB | Government | Level 1 | Fair Value    
Change in plan assets    
Fair value of plan assets at beginning of year 42  
Fair value of plan assets at end of year 71 42
US | OPEB | Government | Level 2 | Fair Value    
Change in plan assets    
Fair value of plan assets at beginning of year 3  
Fair value of plan assets at end of year 6 3
US | OPEB | Government | Level 3 | Fair Value    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
US | OPEB | Corporate | Fair Value    
Change in plan assets    
Fair value of plan assets at beginning of year 12  
Fair value of plan assets at end of year 19 12
US | OPEB | Corporate | Level 1 | Fair Value    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year 0 0
US | OPEB | Corporate | Level 2 | Fair Value    
Change in plan assets    
Fair value of plan assets at beginning of year 12  
Fair value of plan assets at end of year 19 12
US | OPEB | Corporate | Level 3 | Fair Value    
Change in plan assets    
Fair value of plan assets at beginning of year 0  
Fair value of plan assets at end of year $ 0 $ 0