EMPLOYEE POST-RETIREMENT BENEFITS - Measured at Fair Value (Details) - CAD ($) $ in Millions | Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 4,576 | $ 4,479 | |
Percentage of Total Portfolio | 100.00% | 100.00% | |
Quoted Prices in Active Markets (Level I) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 1,946 | $ 1,938 | |
Significant Other Observable Inputs (Level II) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 2,065 | 2,124 | |
Significant Unobservable Inputs (Level III) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 565 | 417 | $ 379 |
Cash and Cash Equivalents | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 70 | $ 87 | |
Percentage of Total Portfolio | 2.00% | 2.00% | |
Cash and Cash Equivalents | Quoted Prices in Active Markets (Level I) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 68 | $ 87 | |
Cash and Cash Equivalents | Significant Other Observable Inputs (Level II) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 2 | 0 | |
Cash and Cash Equivalents | Significant Unobservable Inputs (Level III) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 0 | 0 | |
Equity Securities, Canadian | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 417 | $ 453 | |
Percentage of Total Portfolio | 9.00% | 10.00% | |
Equity Securities, Canadian | Quoted Prices in Active Markets (Level I) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 269 | $ 276 | |
Equity Securities, Canadian | Significant Other Observable Inputs (Level II) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 148 | 177 | |
Equity Securities, Canadian | Significant Unobservable Inputs (Level III) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 0 | 0 | |
Equity Securities, U.S. | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 813 | $ 805 | |
Percentage of Total Portfolio | 18.00% | 18.00% | |
Equity Securities, U.S. | Quoted Prices in Active Markets (Level I) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 649 | $ 594 | |
Equity Securities, U.S. | Significant Other Observable Inputs (Level II) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 164 | 211 | |
Equity Securities, U.S. | Significant Unobservable Inputs (Level III) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 0 | 0 | |
Equity Securities, International | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 480 | $ 494 | |
Percentage of Total Portfolio | 10.00% | 11.00% | |
Equity Securities, International | Quoted Prices in Active Markets (Level I) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 126 | $ 114 | |
Equity Securities, International | Significant Other Observable Inputs (Level II) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 354 | 380 | |
Equity Securities, International | Significant Unobservable Inputs (Level III) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 0 | 0 | |
Equity Securities, Global | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 424 | $ 484 | |
Percentage of Total Portfolio | 9.00% | 11.00% | |
Equity Securities, Global | Quoted Prices in Active Markets (Level I) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 111 | $ 116 | |
Equity Securities, Global | Significant Other Observable Inputs (Level II) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 313 | 368 | |
Equity Securities, Global | Significant Unobservable Inputs (Level III) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 0 | 0 | |
Equity Securities, Emerging | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 145 | $ 160 | |
Percentage of Total Portfolio | 3.00% | 4.00% | |
Equity Securities, Emerging | Quoted Prices in Active Markets (Level I) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 25 | $ 35 | |
Equity Securities, Emerging | Significant Other Observable Inputs (Level II) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 120 | 125 | |
Equity Securities, Emerging | Significant Unobservable Inputs (Level III) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 0 | 0 | |
Fixed Income Securities, Canadian Bonds, Federal | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 226 | $ 207 | |
Percentage of Total Portfolio | 5.00% | 5.00% | |
Fixed Income Securities, Canadian Bonds, Federal | Quoted Prices in Active Markets (Level I) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 0 | $ 0 | |
Fixed Income Securities, Canadian Bonds, Federal | Significant Other Observable Inputs (Level II) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 226 | 207 | |
Fixed Income Securities, Canadian Bonds, Federal | Significant Unobservable Inputs (Level III) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 0 | 0 | |
Fixed Income Securities, Canadian Bonds, Provincial | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 331 | $ 283 | |
Percentage of Total Portfolio | 7.00% | 6.00% | |
Fixed Income Securities, Canadian Bonds, Provincial | Quoted Prices in Active Markets (Level I) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 0 | $ 0 | |
Fixed Income Securities, Canadian Bonds, Provincial | Significant Other Observable Inputs (Level II) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 331 | 283 | |
Fixed Income Securities, Canadian Bonds, Provincial | Significant Unobservable Inputs (Level III) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 0 | 0 | |
Fixed Income Securities, Canadian Bonds, Municipal | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 16 | $ 13 | |
Percentage of Total Portfolio | 0.00% | 0.00% | |
Fixed Income Securities, Canadian Bonds, Municipal | Quoted Prices in Active Markets (Level I) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 0 | $ 0 | |
Fixed Income Securities, Canadian Bonds, Municipal | Significant Other Observable Inputs (Level II) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 16 | 13 | |
Fixed Income Securities, Canadian Bonds, Municipal | Significant Unobservable Inputs (Level III) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 0 | 0 | |
Fixed Income Securities, Canadian Bonds, Corporate | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 147 | $ 151 | |
Percentage of Total Portfolio | 4.00% | 3.00% | |
Fixed Income Securities, Canadian Bonds, Corporate | Quoted Prices in Active Markets (Level I) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 0 | $ 0 | |
Fixed Income Securities, Canadian Bonds, Corporate | Significant Other Observable Inputs (Level II) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 147 | 151 | |
Fixed Income Securities, Canadian Bonds, Corporate | Significant Unobservable Inputs (Level III) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 0 | 0 | |
Fixed Income Securities, U.S. Bonds, Federal | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 448 | $ 458 | |
Percentage of Total Portfolio | 10.00% | 10.00% | |
Fixed Income Securities, U.S. Bonds, Federal | Quoted Prices in Active Markets (Level I) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 433 | $ 444 | |
Fixed Income Securities, U.S. Bonds, Federal | Significant Other Observable Inputs (Level II) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 15 | 14 | |
Fixed Income Securities, U.S. Bonds, Federal | Significant Unobservable Inputs (Level III) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 0 | 0 | |
Fixed Income Securities, U.S. Bonds, Municipal | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 1 | $ 2 | |
Percentage of Total Portfolio | 0.00% | 0.00% | |
Fixed Income Securities, U.S. Bonds, Municipal | Quoted Prices in Active Markets (Level I) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 0 | $ 0 | |
Fixed Income Securities, U.S. Bonds, Municipal | Significant Other Observable Inputs (Level II) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 1 | 2 | |
Fixed Income Securities, U.S. Bonds, Municipal | Significant Unobservable Inputs (Level III) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 0 | 0 | |
Fixed Income Securities, U.S. Bonds, Corporate | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 210 | $ 215 | |
Percentage of Total Portfolio | 5.00% | 5.00% | |
Fixed Income Securities, U.S. Bonds, Corporate | Quoted Prices in Active Markets (Level I) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 67 | $ 72 | |
Fixed Income Securities, U.S. Bonds, Corporate | Significant Other Observable Inputs (Level II) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 143 | 143 | |
Fixed Income Securities, U.S. Bonds, Corporate | Significant Unobservable Inputs (Level III) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 0 | 0 | |
Fixed Income Securities, International, Government | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 13 | $ 14 | |
Percentage of Total Portfolio | 0.00% | 0.00% | |
Fixed Income Securities, International, Government | Quoted Prices in Active Markets (Level I) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 6 | $ 8 | |
Fixed Income Securities, International, Government | Significant Other Observable Inputs (Level II) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 7 | 6 | |
Fixed Income Securities, International, Government | Significant Unobservable Inputs (Level III) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 0 | 0 | |
Fixed Income Securities, International, Corporate | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 73 | $ 48 | |
Percentage of Total Portfolio | 2.00% | 1.00% | |
Fixed Income Securities, International, Corporate | Quoted Prices in Active Markets (Level I) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 0 | $ 0 | |
Fixed Income Securities, International, Corporate | Significant Other Observable Inputs (Level II) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 73 | 48 | |
Fixed Income Securities, International, Corporate | Significant Unobservable Inputs (Level III) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 0 | 0 | |
Fixed Income Securities, International, Mortgage-backed | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 47 | $ 51 | |
Percentage of Total Portfolio | 1.00% | 1.00% | |
Fixed Income Securities, International, Mortgage-backed | Quoted Prices in Active Markets (Level I) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 42 | $ 47 | |
Fixed Income Securities, International, Mortgage-backed | Significant Other Observable Inputs (Level II) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 5 | 4 | |
Fixed Income Securities, International, Mortgage-backed | Significant Unobservable Inputs (Level III) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 0 | 0 | |
Real estate | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 283 | $ 213 | |
Percentage of Total Portfolio | 6.00% | 5.00% | |
Real estate | Quoted Prices in Active Markets (Level I) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 0 | $ 0 | |
Real estate | Significant Other Observable Inputs (Level II) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 0 | 0 | |
Real estate | Significant Unobservable Inputs (Level III) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 283 | 213 | |
Infrastructure | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 281 | $ 203 | |
Percentage of Total Portfolio | 6.00% | 5.00% | |
Infrastructure | Quoted Prices in Active Markets (Level I) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 0 | $ 0 | |
Infrastructure | Significant Other Observable Inputs (Level II) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 0 | 0 | |
Infrastructure | Significant Unobservable Inputs (Level III) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 281 | 203 | |
Private equity funds | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 1 | $ 1 | |
Percentage of Total Portfolio | 0.00% | 0.00% | |
Private equity funds | Quoted Prices in Active Markets (Level I) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 0 | $ 0 | |
Private equity funds | Significant Other Observable Inputs (Level II) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 0 | 0 | |
Private equity funds | Significant Unobservable Inputs (Level III) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 1 | 1 | |
Derivatives | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 0 | $ (8) | |
Percentage of Total Portfolio | 0.00% | 0.00% | |
Derivatives | Quoted Prices in Active Markets (Level I) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 0 | $ 0 | |
Derivatives | Significant Other Observable Inputs (Level II) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 0 | (8) | |
Derivatives | Significant Unobservable Inputs (Level III) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 0 | 0 | |
Funds held on deposit | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 150 | $ 145 | |
Percentage of Total Portfolio | 3.00% | 3.00% | |
Funds held on deposit | Quoted Prices in Active Markets (Level I) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 150 | $ 145 | |
Funds held on deposit | Significant Other Observable Inputs (Level II) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | 0 | 0 | |
Funds held on deposit | Significant Unobservable Inputs (Level III) | | | |
Employee post-retirement benefits | | | |
Fair value of plan assets | $ 0 | $ 0 | |