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Employee Benefit Plans (Change in AOCI ) (Details) CAD in Millions | 12 Months Ended
--- | ---
Dec. 31, 2016 CAD
Pension Plan [Member] |
Defined Benefit Plan Disclosure [Line Items] |
Balance, January 1 | CAD 349
Balance, December 31 | 636
Pension Plan [Member] | Defined Benefit Plans Adjustment, Net Gain (Loss) Including Portion Attributable to Noncontrolling Interest [Member] |
Defined Benefit Plan Disclosure [Line Items] |
Balance, January 1 | 353
Amortized in current period, Net Actuarial Gain (Loss) | (42)
Current year addition to AOCI | 19
Adjustments for MPS | 0
Foreign currency translation adjustment | 0
Balance, December 31 | 330
Pension Plan [Member] | Accumulated Defined Benefit Plans Adjustment, Net Prior Service Including Portion Attributable to Noncontrolling Interest [Member] |
Defined Benefit Plan Disclosure [Line Items] |
Balance, January 1 | (4)
Amortized in current period, Net Prior Service Cost (Credit) | 1
Current year addition to AOCI | 0
Adjustments for MPS | 0
Foreign currency translation adjustment | 0
Balance, December 31 | (3)
Pension Plan [Member] | Regulatory Assets [Member] |
Defined Benefit Plan Disclosure [Line Items] |
Balance, January 1 | 0
Amortized in current period, Net Actuarial Gain (Loss) | (9)
Current year addition to AOCI | 318
Adjustments for MPS | 0
Foreign currency translation adjustment | 0
Balance, December 31 | 309
Non-pension Benefit Plans [Member |
Defined Benefit Plan Disclosure [Line Items] |
Balance, January 1 | (12)
Balance, December 31 | 44
Non-pension Benefit Plans [Member | Defined Benefit Plans Adjustment, Net Gain (Loss) Including Portion Attributable to Noncontrolling Interest [Member] |
Defined Benefit Plan Disclosure [Line Items] |
Balance, January 1 | 15
Amortized in current period, Net Actuarial Gain (Loss) | (2)
Current year addition to AOCI | 2
Adjustments for MPS | 0
Foreign currency translation adjustment | 0
Balance, December 31 | 15
Non-pension Benefit Plans [Member | Accumulated Defined Benefit Plans Adjustment, Net Prior Service Including Portion Attributable to Noncontrolling Interest [Member] |
Defined Benefit Plan Disclosure [Line Items] |
Balance, January 1 | (27)
Amortized in current period, Net Prior Service Cost (Credit) | 8
Current year addition to AOCI | 0
Adjustments for MPS | 0
Foreign currency translation adjustment | 0
Balance, December 31 | (19)
Non-pension Benefit Plans [Member | Regulatory Assets [Member] |
Defined Benefit Plan Disclosure [Line Items] |
Balance, January 1 | 0
Amortized in current period, Net Actuarial Gain (Loss) | 0
Current year addition to AOCI | 48
Adjustments for MPS | 0
Foreign currency translation adjustment | 0
Balance, December 31 | CAD 48

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- Definition The pretax total of net gain (loss), prior service cost (credit), and transition assets (obligations), as well as minimum pension liability if still remaining, included in accumulated other comprehensive income associated with a defined benefit pension or other postretirement plan(s) because they have yet to be recognized as components of net periodic benefit cost. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (j) -URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 10A -Subparagraph (i-k) -URI http://asc.fasb.org/extlink&oid=66004124&loc=SL7669646-108580 + Details
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- Definition Amount before tax, after reclassification adjustments, of actuarial gain (loss) that has not been recognized in the income statement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 10A -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=66004124&loc=SL7669646-108580 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920 + Details
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- Definition Amount before tax, after reclassification adjustments, of prior service cost (credit) that has not been recognized in the income statement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 10A -Subparagraph (j) -URI http://asc.fasb.org/extlink&oid=66004124&loc=SL7669646-108580 + Details
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- Definition Amount before tax of gain (loss) adjustment to other comprehensive income (loss) resulting from settlement or curtailment of defined benefit pension and other postretirement defined benefit plans. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=66004124&loc=d3e637-108580 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a)(10) -URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Plan Curtailment -URI http://asc.fasb.org/extlink&oid=6520938 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Settlement of a Pension or Postretirement Benefit Obligation -URI http://asc.fasb.org/extlink&oid=6531942 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h)(7) -URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (j) -URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920 + Details
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- Definition Amount before tax, after reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 20 -Section 35 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6939497&loc=d3e30304-110892 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=66004124&loc=d3e637-108580 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -Section 45 -Paragraph 20 -Subparagraph (b,d) -URI http://asc.fasb.org/extlink&oid=64808268&loc=d3e32211-110900 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 10A -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66004124&loc=SL7669646-108580 + Details
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