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Employee Benefit Plans (Fair Value of Investments) (Details) - CAD ($) $ in Millions | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
--- | --- | --- | ---
Classification of the methodology used by the Company to fair value its investments |  |  |
Percentage | 100.00% | 100.00% |
Defined benefit pension plans |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | $ 2,593 | $ 2,300 | $ 2,408
Cash and cash equivalents |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Percentage |  | 1.00% |
Net in-transits |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Percentage | (2.00%) | (2.00%) |
Canadian equity |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Percentage |  | 8.00% |
US equity |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Percentage |  | 14.00% |
Other equity |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Percentage | 7.00% | 7.00% |
Government |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Percentage | 3.00% | 5.00% |
Corporate |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Percentage |  | 5.00% |
Other |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Percentage |  | 0.00% |
Mutual funds |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Percentage |  | 6.00% |
Other |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Percentage |  | 1.00% |
Open-ended investments measured at NAV |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Percentage | 33.00% | 36.00% |
Common collective trusts measured at NAV |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Percentage | 21.00% | 19.00% |
Total |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | $ 2,593 | $ 2,300 |
Percentage | 100.00% |  |
Total | Cash and cash equivalents |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | $ 44 | 30 |
Percentage | 2.00% |  |
Total | Net in-transits |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | $ (48) | (56) |
Percentage | (2.00%) |  |
Total | Canadian equity |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | $ 210 | 191 |
Percentage | 8.00% |  |
Total | US equity |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | $ 388 | 330 |
Percentage | 15.00% |  |
Total | Other equity |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | $ 176 | 157 |
Percentage | 7.00% |  |
Total | Government |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | $ 93 | 119 |
Percentage | 3.00% |  |
Total | Corporate |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | $ 126 | 108 |
Percentage | 5.00% |  |
Total | Other |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | $ 14 | 7 |
Percentage | 0.00% |  |
Total | Mutual funds |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | $ 199 | 132 |
Percentage | 8.00% |  |
Total | Other |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | $ (4) | 12 |
Percentage | 0.00% |  |
Total | Open-ended investments measured at NAV |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | $ 860 | 820 |
Percentage | 33.00% |  |
Total | Common collective trusts measured at NAV |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | $ 535 | 450 |
Percentage | 21.00% |  |
NAV |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | $ 1,395 | 1,270 |
NAV | Cash and cash equivalents |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 0 | 0 |
NAV | Net in-transits |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 0 | 0 |
NAV | Canadian equity |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 0 | 0 |
NAV | US equity |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 0 | 0 |
NAV | Other equity |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 0 | 0 |
NAV | Government |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 0 | 0 |
NAV | Corporate |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 0 | 0 |
NAV | Other |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 0 | 0 |
NAV | Mutual funds |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 0 | 0 |
NAV | Other |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 0 | 0 |
NAV | Open-ended investments measured at NAV |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 860 | 820 |
NAV | Common collective trusts measured at NAV |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 535 | 450 |
Level 1 |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 969 | 796 |
Level 1 | Cash and cash equivalents |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 44 | 30 |
Level 1 | Net in-transits |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | (48) | (56) |
Level 1 | Canadian equity |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 210 | 191 |
Level 1 | US equity |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 388 | 330 |
Level 1 | Other equity |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 176 | 157 |
Level 1 | Government |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 0 | 0 |
Level 1 | Corporate |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 0 | 0 |
Level 1 | Other |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 5 | 4 |
Level 1 | Mutual funds |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 199 | 132 |
Level 1 | Other |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | (5) | 8 |
Level 1 | Open-ended investments measured at NAV |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 0 | 0 |
Level 1 | Common collective trusts measured at NAV |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 0 | 0 |
Level 2 |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 229 | 234 |
Level 2 | Cash and cash equivalents |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 0 | 0 |
Level 2 | Net in-transits |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 0 | 0 |
Level 2 | Canadian equity |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 0 | 0 |
Level 2 | US equity |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 0 | 0 |
Level 2 | Other equity |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 0 | 0 |
Level 2 | Government |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 93 | 119 |
Level 2 | Corporate |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 126 | 108 |
Level 2 | Other |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 9 | 3 |
Level 2 | Mutual funds |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 0 | 0 |
Level 2 | Other |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 1 | 4 |
Level 2 | Open-ended investments measured at NAV |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | 0 | 0 |
Level 2 | Common collective trusts measured at NAV |  |  |
Classification of the methodology used by the Company to fair value its investments |  |  |
Fair Value of Plan Assets | $ 0 | $ 0 |

X
- Definition Amount of asset segregated and restricted to provide benefit under defined benefit plan. Asset includes, but is not limited to, stock, bond, other investment, earning from investment, and contribution by employer and employee. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(01) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(01) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(ii) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=118257860&loc=d3e4179-114921 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(ii) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 + Details
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- Definition Percentage of actual investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(i) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 + Details
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