Revenue (Disaggregation) (Details) - CAD ($) $ in Millions | 12 Months Ended |
Dec. 31, 2019 | Dec. 31, 2018 |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | $ 6,111 | $ 6,524 |
Total operating revenues | 6,111 | 6,524 |
Florida Electric Utility | | |
Disaggregation of Revenue [Line Items] | | |
Total operating revenues | 2,607 | 2,679 |
Canadian Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Total operating revenues | 1,430 | 1,440 |
Other Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Total operating revenues | 744 | 745 |
Gas Utilities and Infrastructure | | |
Disaggregation of Revenue [Line Items] | | |
Total operating revenues | 1,119 | 1,098 |
Other | | |
Disaggregation of Revenue [Line Items] | | |
Total operating revenues | 282 | 661 |
Operating | | |
Disaggregation of Revenue [Line Items] | | |
Total operating revenues | 6,111 | 6,524 |
Operating | Florida Electric Utility | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 2,607 | 2,679 |
Total operating revenues | 2,596 | 2,670 |
Operating | Canadian Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 1,430 | 1,440 |
Total operating revenues | 1,429 | 1,437 |
Operating | Other Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 744 | 745 |
Total operating revenues | 744 | 745 |
Operating | Gas Utilities and Infrastructure | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 1,119 | 1,098 |
Total operating revenues | 1,097 | 1,062 |
Operating | Other | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 282 | 661 |
Total operating revenues | 245 | 610 |
Eliminations | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | (71) | (99) |
Total operating revenues | (43) | (54) |
Eliminations | Florida Electric Utility | | |
Disaggregation of Revenue [Line Items] | | |
Total operating revenues | 11 | 9 |
Eliminations | Canadian Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Total operating revenues | 1 | 3 |
Eliminations | Other Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Total operating revenues | 0 | 0 |
Eliminations | Gas Utilities and Infrastructure | | |
Disaggregation of Revenue [Line Items] | | |
Total operating revenues | 22 | 36 |
Eliminations | Other | | |
Disaggregation of Revenue [Line Items] | | |
Total operating revenues | 37 | 51 |
Non-Regulated | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 261 | 628 |
Total operating revenues | 261 | 628 |
Non-Regulated | Capacity | | |
Disaggregation of Revenue [Line Items] | | |
Total operating revenues | 38 | 136 |
Non-Regulated | Operating | Florida Electric Utility | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Non-Regulated | Operating | Florida Electric Utility | Capacity | | |
Disaggregation of Revenue [Line Items] | | |
Total operating revenues | 0 | 0 |
Non-Regulated | Operating | Canadian Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Non-Regulated | Operating | Canadian Electric Utilities | Capacity | | |
Disaggregation of Revenue [Line Items] | | |
Total operating revenues | 0 | 0 |
Non-Regulated | Operating | Other Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Non-Regulated | Operating | Other Electric Utilities | Capacity | | |
Disaggregation of Revenue [Line Items] | | |
Total operating revenues | 0 | 0 |
Non-Regulated | Operating | Gas Utilities and Infrastructure | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 16 | 18 |
Non-Regulated | Operating | Gas Utilities and Infrastructure | Capacity | | |
Disaggregation of Revenue [Line Items] | | |
Total operating revenues | 0 | 0 |
Non-Regulated | Operating | Other | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 282 | 661 |
Non-Regulated | Operating | Other | Capacity | | |
Disaggregation of Revenue [Line Items] | | |
Total operating revenues | 38 | 136 |
Non-Regulated | Eliminations | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | (37) | (51) |
Non-Regulated | Eliminations | Capacity | | |
Disaggregation of Revenue [Line Items] | | |
Total operating revenues | 0 | 0 |
Electric | Regulated | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 4,769 | 4,852 |
Total operating revenues | 4,769 | 4,852 |
Electric | Regulated | Operating | Florida Electric Utility | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 2,607 | 2,679 |
Electric | Regulated | Operating | Canadian Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 1,430 | 1,440 |
Electric | Regulated | Operating | Other Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 744 | 745 |
Electric | Regulated | Operating | Gas Utilities and Infrastructure | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Electric | Regulated | Operating | Other | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Electric | Regulated | Eliminations | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | (12) | (12) |
Electric | Regulated | Residential | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 2,409 | 2,376 |
Electric | Regulated | Residential | Operating | Florida Electric Utility | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 1,387 | 1,384 |
Electric | Regulated | Residential | Operating | Canadian Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 746 | 731 |
Electric | Regulated | Residential | Operating | Other Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 276 | 261 |
Electric | Regulated | Residential | Operating | Gas Utilities and Infrastructure | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Electric | Regulated | Residential | Operating | Other | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Electric | Regulated | Residential | Eliminations | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Electric | Regulated | Commercial | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 1,484 | 1,510 |
Electric | Regulated | Commercial | Operating | Florida Electric Utility | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 745 | 755 |
Electric | Regulated | Commercial | Operating | Canadian Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 400 | 405 |
Electric | Regulated | Commercial | Operating | Other Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 339 | 350 |
Electric | Regulated | Commercial | Operating | Gas Utilities and Infrastructure | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Electric | Regulated | Commercial | Operating | Other | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Electric | Regulated | Commercial | Eliminations | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Electric | Regulated | Industrial | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 461 | 488 |
Electric | Regulated | Industrial | Operating | Florida Electric Utility | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 207 | 209 |
Electric | Regulated | Industrial | Operating | Canadian Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 210 | 233 |
Electric | Regulated | Industrial | Operating | Other Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 44 | 46 |
Electric | Regulated | Industrial | Operating | Gas Utilities and Infrastructure | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Electric | Regulated | Industrial | Operating | Other | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Electric | Regulated | Industrial | Eliminations | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Electric | Regulated | Other Electric And Regulatory | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 304 | 371 |
Electric | Regulated | Other Electric And Regulatory | Operating | Florida Electric Utility | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 246 | 312 |
Electric | Regulated | Other Electric And Regulatory | Operating | Canadian Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 45 | 43 |
Electric | Regulated | Other Electric And Regulatory | Operating | Other Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 13 | 16 |
Electric | Regulated | Other Electric And Regulatory | Operating | Gas Utilities and Infrastructure | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Electric | Regulated | Other Electric And Regulatory | Operating | Other | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Electric | Regulated | Other Electric And Regulatory | Eliminations | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Electric | Regulated | Other | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 111 | 107 |
Electric | Regulated | Other | Operating | Florida Electric Utility | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 22 | 19 |
Electric | Regulated | Other | Operating | Canadian Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 29 | 28 |
Electric | Regulated | Other | Operating | Other Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 72 | 72 |
Electric | Regulated | Other | Operating | Gas Utilities and Infrastructure | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Electric | Regulated | Other | Operating | Other | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Electric | Regulated | Other | Eliminations | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | (12) | (12) |
Gas | Regulated | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 1,081 | 1,044 |
Total operating revenues | 1,081 | 1,044 |
Gas | Regulated | Operating | Florida Electric Utility | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Operating | Canadian Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Operating | Other Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Operating | Gas Utilities and Infrastructure | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 1,103 | 1,080 |
Gas | Regulated | Operating | Other | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Eliminations | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | (22) | (36) |
Gas | Regulated | Residential | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 502 | 492 |
Gas | Regulated | Residential | Operating | Florida Electric Utility | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Residential | Operating | Canadian Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Residential | Operating | Other Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Residential | Operating | Gas Utilities and Infrastructure | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 502 | 492 |
Gas | Regulated | Residential | Operating | Other | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Residential | Eliminations | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Commercial | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 298 | 291 |
Gas | Regulated | Commercial | Operating | Florida Electric Utility | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Commercial | Operating | Canadian Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Commercial | Operating | Other Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Commercial | Operating | Gas Utilities and Infrastructure | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 298 | 291 |
Gas | Regulated | Commercial | Operating | Other | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Commercial | Eliminations | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Industrial | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 50 | 49 |
Gas | Regulated | Industrial | Operating | Florida Electric Utility | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Industrial | Operating | Canadian Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Industrial | Operating | Other Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Industrial | Operating | Gas Utilities and Infrastructure | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 50 | 49 |
Gas | Regulated | Industrial | Operating | Other | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Industrial | Eliminations | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Finance Income | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 60 | 57 |
Gas | Regulated | Finance Income | Operating | Florida Electric Utility | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Finance Income | Operating | Canadian Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Finance Income | Operating | Other Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Finance Income | Operating | Gas Utilities and Infrastructure | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 60 | 57 |
Gas | Regulated | Finance Income | Operating | Other | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Finance Income | Eliminations | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Other | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 171 | 155 |
Gas | Regulated | Other | Operating | Florida Electric Utility | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Other | Operating | Canadian Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Other | Operating | Other Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Other | Operating | Gas Utilities and Infrastructure | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 193 | 191 |
Gas | Regulated | Other | Operating | Other | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Gas | Regulated | Other | Eliminations | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | (22) | (36) |
Marketing and trading margin | Non-Regulated | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 31 | 115 |
Marketing and trading margin | Non-Regulated | Operating | Florida Electric Utility | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Marketing and trading margin | Non-Regulated | Operating | Canadian Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Marketing and trading margin | Non-Regulated | Operating | Other Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Marketing and trading margin | Non-Regulated | Operating | Gas Utilities and Infrastructure | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Marketing and trading margin | Non-Regulated | Operating | Other | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 31 | 115 |
Marketing and trading margin | Non-Regulated | Eliminations | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Energy sales | Non-Regulated | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 68 | 293 |
Energy sales | Non-Regulated | Operating | Florida Electric Utility | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Energy sales | Non-Regulated | Operating | Canadian Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Energy sales | Non-Regulated | Operating | Other Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Energy sales | Non-Regulated | Operating | Gas Utilities and Infrastructure | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Energy sales | Non-Regulated | Operating | Other | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 80 | 309 |
Energy sales | Non-Regulated | Eliminations | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | (12) | (16) |
Other | Non-Regulated | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 22 | 30 |
Other | Non-Regulated | Operating | Florida Electric Utility | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Other | Non-Regulated | Operating | Canadian Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Other | Non-Regulated | Operating | Other Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Other | Non-Regulated | Operating | Gas Utilities and Infrastructure | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 16 | 18 |
Other | Non-Regulated | Operating | Other | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 31 | 47 |
Other | Non-Regulated | Eliminations | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | (25) | (35) |
Mark-To-Market | Non-Regulated | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 102 | 54 |
Mark-To-Market | Non-Regulated | Operating | Florida Electric Utility | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Mark-To-Market | Non-Regulated | Operating | Canadian Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Mark-To-Market | Non-Regulated | Operating | Other Electric Utilities | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Mark-To-Market | Non-Regulated | Operating | Gas Utilities and Infrastructure | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 0 | 0 |
Mark-To-Market | Non-Regulated | Operating | Other | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | 102 | 54 |
Mark-To-Market | Non-Regulated | Eliminations | | |
Disaggregation of Revenue [Line Items] | | |
Revenue from contract with customer | $ 0 | $ 0 |