CONDENSED CONSOLIDATING FINANCIAL INFORMATION - Condensed Consolidating Statements of Earnings and Comprehensive Income (Details) - CAD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Condensed Statement of Income Captions [Line Items]
Total operating revenues	$ 12,352	$ 11,598	$ 13,263	$ 12,856	$ 11,562	$ 11,345	$ 10,745	$ 12,726	$ 50,069	$ 46,378	$ 44,378
Operating and administrative									6,991	6,792	6,442
Depreciation and amortization									3,391	3,246	3,163
Impairment of long-lived assets (Note 8 and Note 11)									423	1,104	4,463
Impairment of goodwill (Note 8 and Note 16)									0	1,019	102
Total operating expenses									41,809	41,562	42,807
Operating income	1,768	1,588	2,285	2,619	1,513	854	1,571	878	8,260	4,816	1,571
Income from equity investments (Note 13)									1,503	1,509	1,102
Equity earnings from consolidated subsidiaries									0	0	0
Net foreign currency gain/(loss)									477	(522)	237
Gain/(loss) on dispositions									(300)	(46)	16
Other, including other income/(expense) from affiliates									258	516	199
Interest expense									(2,663)	(2,703)	(2,556)
Earnings before income taxes									7,535	3,570	569
Income tax recovery/(expense) (Note 25)									(1,708)	(237)	2,697
Earnings	914	1,060	1,830	2,023	1,283	213	1,327	510	5,827	3,333	3,266
Earnings attributable to noncontrolling interests and redeemable noncontrolling interests									(122)	(451)	(407)
Earnings attributable to controlling interests	842	1,045	1,832	1,986	1,184	4	1,160	534	5,705	2,882	2,859
Preference share dividends									(383)	(367)	(330)
Earnings attributable to common shareholders	$ 746	$ 949	$ 1,736	$ 1,891	$ 1,089	$ (90)	$ 1,071	$ 445	5,322	2,515	2,529
Earnings									5,827	3,333	3,266
Other comprehensive income/(loss), net of tax									(3,107)	4,138	(2,278)
Comprehensive income									2,720	7,471	988
Comprehensive income attributable to noncontrolling interests and redeemable noncontrolling interests									(7)	(801)	(160)
Comprehensive income attributable to controlling interests									2,713	6,670	828
Eliminations and Other
Condensed Statement of Income Captions [Line Items]
Total operating revenues									0	0	0
Operating and administrative									0	(78)	0
Depreciation and amortization									0	0	0
Impairment of long-lived assets (Note 8 and Note 11)									0	0	0
Impairment of goodwill (Note 8 and Note 16)									0	0	0
Total operating expenses									0	(78)	0
Operating income									0	78	0
Income from equity investments (Note 13)									(66)	(295)	(468)
Equity earnings from consolidated subsidiaries									(7,809)	(825)	(4,689)
Net foreign currency gain/(loss)									(1,088)	219	(241)
Gain/(loss) on dispositions									0	0	0
Other, including other income/(expense) from affiliates									(2,450)	(908)	(896)
Interest expense									2,492	925	925
Earnings before income taxes									(8,921)	(806)	(5,369)
Income tax recovery/(expense) (Note 25)									618	4,148	43
Earnings									(8,303)	3,342	(5,326)
Earnings attributable to noncontrolling interests and redeemable noncontrolling interests									(122)	(451)	(407)
Earnings attributable to controlling interests									(8,425)	2,891	(5,733)
Preference share dividends									0	0	0
Earnings attributable to common shareholders									(8,425)	2,891	(5,733)
Earnings									(8,303)	3,342	(5,326)
Other comprehensive income/(loss), net of tax									830	(225)	(51)
Comprehensive income									(7,473)	3,117	(5,377)
Comprehensive income attributable to noncontrolling interests and redeemable noncontrolling interests									(7)	(801)	(160)
Comprehensive income attributable to controlling interests									(7,480)	2,316	(5,537)
Parent Issuer and Guarantor | Parent and Subsidiaries
Condensed Statement of Income Captions [Line Items]
Total operating revenues									0	0	0
Operating and administrative									128	180	169
Depreciation and amortization									67	59	56
Impairment of long-lived assets (Note 8 and Note 11)									0	0	0
Impairment of goodwill (Note 8 and Note 16)									0	0	0
Total operating expenses									195	239	225
Operating income									(195)	(239)	(225)
Income from equity investments (Note 13)									70	302	471
Equity earnings from consolidated subsidiaries									3,881	3,119	2,130
Net foreign currency gain/(loss)									1,671	(829)	500
Gain/(loss) on dispositions									(7)	360	(11)
Other, including other income/(expense) from affiliates									1,944	945	871
Interest expense									(1,268)	(1,080)	(816)
Earnings before income taxes									6,096	2,578	2,920
Income tax recovery/(expense) (Note 25)									(391)	304	(61)
Earnings									5,705	2,882	2,859
Earnings attributable to noncontrolling interests and redeemable noncontrolling interests									0	0	0
Earnings attributable to controlling interests									5,705	2,882	2,859
Preference share dividends									(383)	(367)	(330)
Earnings attributable to common shareholders									5,322	2,515	2,529
Earnings									5,705	2,882	2,859
Other comprehensive income/(loss), net of tax									(2,992)	3,788	(2,031)
Comprehensive income									2,713	6,670	828
Comprehensive income attributable to noncontrolling interests and redeemable noncontrolling interests									0	0	0
Comprehensive income attributable to controlling interests									2,713	6,670	828
Subsidiary Non-Guarantors | Parent and Subsidiaries
Condensed Statement of Income Captions [Line Items]
Total operating revenues									50,069	46,378	44,378
Operating and administrative									6,874	6,622	6,111
Depreciation and amortization									3,324	3,187	3,107
Impairment of long-lived assets (Note 8 and Note 11)									423	1,104	4,463
Impairment of goodwill (Note 8 and Note 16)									0	1,019	102
Total operating expenses									41,625	41,333	42,420
Operating income									8,444	5,045	1,958
Income from equity investments (Note 13)									1,366	1,360	981
Equity earnings from consolidated subsidiaries									1,696	(1,581)	881
Net foreign currency gain/(loss)									(106)	80	(22)
Gain/(loss) on dispositions									(293)	(406)	27
Other, including other income/(expense) from affiliates									573	254	74
Interest expense									(2,966)	(1,689)	(1,753)
Earnings before income taxes									8,714	3,063	2,146
Income tax recovery/(expense) (Note 25)									(1,985)	(4,373)	2,706
Earnings									6,729	(1,310)	4,852
Earnings attributable to noncontrolling interests and redeemable noncontrolling interests									0	0	0
Earnings attributable to controlling interests									6,729	(1,310)	4,852
Preference share dividends									0	0	0
Earnings attributable to common shareholders									6,729	(1,310)	4,852
Earnings									6,729	(1,310)	4,852
Other comprehensive income/(loss), net of tax									(929)	556	(412)
Comprehensive income									5,800	(754)	4,440
Comprehensive income attributable to noncontrolling interests and redeemable noncontrolling interests									0	0	0
Comprehensive income attributable to controlling interests									5,800	(754)	4,440
Spectra Energy Partners, LP | Subsidiary Issuer and Guarantor | Parent and Subsidiaries
Condensed Statement of Income Captions [Line Items]
Total operating revenues									0	0	0
Operating and administrative									5	14	146
Depreciation and amortization									0	0	0
Impairment of long-lived assets (Note 8 and Note 11)									0	0	0
Impairment of goodwill (Note 8 and Note 16)									0	0	0
Total operating expenses									5	14	146
Operating income									(5)	(14)	(146)
Income from equity investments (Note 13)									133	142	118
Equity earnings from consolidated subsidiaries									1,189	(1,634)	752
Net foreign currency gain/(loss)									0	8	0
Gain/(loss) on dispositions									0	0	0
Other, including other income/(expense) from affiliates									2	72	11
Interest expense									(330)	(302)	(221)
Earnings before income taxes									989	(1,728)	514
Income tax recovery/(expense) (Note 25)									44	(319)	0
Earnings									1,033	(2,047)	514
Earnings attributable to noncontrolling interests and redeemable noncontrolling interests									0	0	0
Earnings attributable to controlling interests									1,033	(2,047)	514
Preference share dividends									0	0	0
Earnings attributable to common shareholders									1,033	(2,047)	514
Earnings									1,033	(2,047)	514
Other comprehensive income/(loss), net of tax									(67)	(9)	12
Comprehensive income									966	(2,056)	526
Comprehensive income attributable to noncontrolling interests and redeemable noncontrolling interests									0	0	0
Comprehensive income attributable to controlling interests									966	(2,056)	526
Enbridge Energy Partners, L.P. | Subsidiary Issuer and Guarantor | Parent and Subsidiaries
Condensed Statement of Income Captions [Line Items]
Total operating revenues									0	0	0
Operating and administrative									(16)	54	16
Depreciation and amortization									0	0	0
Impairment of long-lived assets (Note 8 and Note 11)									0	0	0
Impairment of goodwill (Note 8 and Note 16)									0	0	0
Total operating expenses									(16)	54	16
Operating income									16	(54)	(16)
Income from equity investments (Note 13)									0	0	0
Equity earnings from consolidated subsidiaries									1,043	921	926
Net foreign currency gain/(loss)									0	0	0
Gain/(loss) on dispositions									0	0	0
Other, including other income/(expense) from affiliates									189	153	139
Interest expense									(591)	(557)	(691)
Earnings before income taxes									657	463	358
Income tax recovery/(expense) (Note 25)									6	3	9
Earnings									663	466	367
Earnings attributable to noncontrolling interests and redeemable noncontrolling interests									0	0	0
Earnings attributable to controlling interests									663	466	367
Preference share dividends									0	0	0
Earnings attributable to common shareholders									663	466	367
Earnings									663	466	367
Other comprehensive income/(loss), net of tax									51	28	204
Comprehensive income									714	494	571
Comprehensive income attributable to noncontrolling interests and redeemable noncontrolling interests									0	0	0
Comprehensive income attributable to controlling interests									714	494	571
Commodity sales
Condensed Statement of Income Captions [Line Items]
Total operating revenues									29,309	27,660	26,286
Cost of goods and services sold									28,802	26,818	26,065
Commodity sales | Eliminations and Other
Condensed Statement of Income Captions [Line Items]
Total operating revenues									0	0	0
Cost of goods and services sold									0	0	0
Commodity sales | Parent Issuer and Guarantor | Parent and Subsidiaries
Condensed Statement of Income Captions [Line Items]
Total operating revenues									0	0	0
Cost of goods and services sold									0	0	0
Commodity sales | Subsidiary Non-Guarantors | Parent and Subsidiaries
Condensed Statement of Income Captions [Line Items]
Total operating revenues									29,309	27,660	26,286
Cost of goods and services sold									28,802	26,818	26,065
Commodity sales | Spectra Energy Partners, LP | Subsidiary Issuer and Guarantor | Parent and Subsidiaries
Condensed Statement of Income Captions [Line Items]
Total operating revenues									0	0	0
Cost of goods and services sold									0	0	0
Commodity sales | Enbridge Energy Partners, L.P. | Subsidiary Issuer and Guarantor | Parent and Subsidiaries
Condensed Statement of Income Captions [Line Items]
Total operating revenues									0	0	0
Cost of goods and services sold									0	0	0
Gas distribution revenue
Condensed Statement of Income Captions [Line Items]
Total operating revenues									4,205	4,360	4,215
Cost of goods and services sold									2,202	2,583	2,572
Gas distribution revenue | Eliminations and Other
Condensed Statement of Income Captions [Line Items]
Total operating revenues									0	0	0
Cost of goods and services sold									0	0	0
Gas distribution revenue | Parent Issuer and Guarantor | Parent and Subsidiaries
Condensed Statement of Income Captions [Line Items]
Total operating revenues									0	0	0
Cost of goods and services sold									0	0	0
Gas distribution revenue | Subsidiary Non-Guarantors | Parent and Subsidiaries
Condensed Statement of Income Captions [Line Items]
Total operating revenues									4,205	4,360	4,215
Cost of goods and services sold									2,202	2,583	2,572
Gas distribution revenue | Spectra Energy Partners, LP | Subsidiary Issuer and Guarantor | Parent and Subsidiaries
Condensed Statement of Income Captions [Line Items]
Total operating revenues									0	0	0
Cost of goods and services sold									0	0	0
Gas distribution revenue | Enbridge Energy Partners, L.P. | Subsidiary Issuer and Guarantor | Parent and Subsidiaries
Condensed Statement of Income Captions [Line Items]
Total operating revenues									0	0	0
Cost of goods and services sold									0	0	0
Transportation and other services revenues
Condensed Statement of Income Captions [Line Items]
Total operating revenues									16,555	14,358	13,877
Transportation and other services revenues | Eliminations and Other
Condensed Statement of Income Captions [Line Items]
Total operating revenues									0	0	0
Transportation and other services revenues | Parent Issuer and Guarantor | Parent and Subsidiaries
Condensed Statement of Income Captions [Line Items]
Total operating revenues									0	0	0
Transportation and other services revenues | Subsidiary Non-Guarantors | Parent and Subsidiaries
Condensed Statement of Income Captions [Line Items]
Total operating revenues									16,555	14,358	13,877
Transportation and other services revenues | Spectra Energy Partners, LP | Subsidiary Issuer and Guarantor | Parent and Subsidiaries
Condensed Statement of Income Captions [Line Items]
Total operating revenues									0	0	0
Transportation and other services revenues | Enbridge Energy Partners, L.P. | Subsidiary Issuer and Guarantor | Parent and Subsidiaries
Condensed Statement of Income Captions [Line Items]
Total operating revenues									$ 0	$ 0	$ 0