CONDENSED CONSOLIDATING FINANCIAL INFORMATION - Statements of Cash Flow (Details) - CAD ($) $ in Millions	1 Months Ended	9 Months Ended
	Jan. 31, 2019	Sep. 30, 2019	Sep. 30, 2018
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in)/provided by operating activities		$ 7,405	$ 7,999
Investing activities
Capital expenditures	$ (265)	(3,928)	(4,584)
Long-term investments and restricted long-term investments		(1,018)	(1,091)
Distributions from equity investments in excess of cumulative earnings		285	1,243
Additions to intangible assets		(136)	(491)
Affiliate loans, net		(232)	(50)
Proceeds from dispositions		0	1,913
Reimbursement of capital expenditures			0
Contributions to subsidiaries		0	0
Return of share capital from subsidiaries		0	0
Advances to affiliates		0	0
Repayment of advances to affiliates		0	0
Other		0	(12)
Net cash (used in)/provided by investing activities		(5,029)	(3,072)
Financing activities
Net change in short-term borrowings		245	(196)
Net change in commercial paper and credit facility draws		3,365	(2,358)
Debenture and term note issues, net of issue costs		2,553	3,537
Debenture and term note repayments		(2,994)	(3,757)
Sale of noncontrolling interests in subsidiaries		0	1,289
Contributions from noncontrolling interests		10	23
Distributions to noncontrolling interests		(194)	(637)
Contributions from redeemable noncontrolling interests		0	62
Distributions to redeemable noncontrolling interests		0	(264)
Contributions from parents		0	0
Distributions to parents		0	0
Redemption of preferred shares held by subsidiary (Note 10)		(300)	0
Common shares issued		18	17
Preference share dividends		(287)	(268)
Common share dividends		(4,480)	(2,254)
Advances from affiliates		0	0
Repayment of advances from affiliates		0	0
Other		(60)	(5)
Net cash provided by/(used in) financing activities		(2,124)	(4,811)
Effect of translation of foreign denominated cash and cash equivalents and restricted cash		(17)	23
Net increase/(decrease) in cash and cash equivalents and restricted cash		235	139
Cash and cash equivalents and restricted cash at beginning of period	637	637	587
Cash and cash equivalents and restricted cash at end of period		872	726
Consolidating and elimination adjustments
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in)/provided by operating activities		(3,369)	(2,589)
Investing activities
Capital expenditures		0	0
Long-term investments and restricted long-term investments		0	67
Distributions from equity investments in excess of cumulative earnings		(850)	(858)
Additions to intangible assets		0	0
Affiliate loans, net		0	0
Proceeds from dispositions			0
Reimbursement of capital expenditures			0
Contributions to subsidiaries		2,884	7,267
Return of share capital from subsidiaries		(4,921)	(3,624)
Advances to affiliates		105,973	9,616
Repayment of advances to affiliates		(18,726)	(11,470)
Other			0
Net cash (used in)/provided by investing activities		84,360	998
Financing activities
Net change in short-term borrowings		0	0
Net change in commercial paper and credit facility draws		0	0
Debenture and term note issues, net of issue costs		0	0
Debenture and term note repayments		0	0
Sale of noncontrolling interests in subsidiaries			0
Contributions from noncontrolling interests		10	23
Distributions to noncontrolling interests		(194)	(637)
Contributions from redeemable noncontrolling interests		0	62
Distributions to redeemable noncontrolling interests		0	(264)
Contributions from parents		(2,884)	(7,267)
Distributions to parents		9,324	7,820
Redemption of preferred shares held by subsidiary (Note 10)		0
Common shares issued		0	0
Preference share dividends		0	0
Common share dividends		0	0
Advances from affiliates		(105,973)	(9,616)
Repayment of advances from affiliates		18,726	11,470
Other		0	0
Net cash provided by/(used in) financing activities		(80,991)	1,591
Effect of translation of foreign denominated cash and cash equivalents and restricted cash		0	0
Net increase/(decrease) in cash and cash equivalents and restricted cash		0	0
Cash and cash equivalents and restricted cash at beginning of period	0	0	0
Cash and cash equivalents and restricted cash at end of period		0	0
Parent Issuer and Guarantor | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in)/provided by operating activities		1,766	1,449
Investing activities
Capital expenditures		(56)	(17)
Long-term investments and restricted long-term investments		(19)	(69)
Distributions from equity investments in excess of cumulative earnings		0	65
Additions to intangible assets		(55)	(33)
Affiliate loans, net		0	0
Proceeds from dispositions			0
Reimbursement of capital expenditures			0
Contributions to subsidiaries		(2,876)	(7,179)
Return of share capital from subsidiaries		4,921	3,624
Advances to affiliates		(47,536)	(5,030)
Repayment of advances to affiliates		5,858	7,395
Other			0
Net cash (used in)/provided by investing activities		(39,763)	(1,244)
Financing activities
Net change in short-term borrowings		0	0
Net change in commercial paper and credit facility draws		4,342	(341)
Debenture and term note issues, net of issue costs		0	2,556
Debenture and term note repayments		(1,450)	0
Sale of noncontrolling interests in subsidiaries			0
Contributions from noncontrolling interests		0	0
Distributions to noncontrolling interests		0	0
Contributions from redeemable noncontrolling interests		0	0
Distributions to redeemable noncontrolling interests		0	0
Contributions from parents		0	0
Distributions to parents		0	0
Redemption of preferred shares held by subsidiary (Note 10)		0
Common shares issued		18	17
Preference share dividends		(287)	(268)
Common share dividends		(4,480)	(2,254)
Advances from affiliates		46,917	535
Repayment of advances from affiliates		(7,063)	(443)
Other		0	0
Net cash provided by/(used in) financing activities		37,997	(198)
Effect of translation of foreign denominated cash and cash equivalents and restricted cash		0	0
Net increase/(decrease) in cash and cash equivalents and restricted cash		0	7
Cash and cash equivalents and restricted cash at beginning of period	9	9	2
Cash and cash equivalents and restricted cash at end of period		9	9
Subsidiary Non-Guarantors | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in)/provided by operating activities		6,676	7,901
Investing activities
Capital expenditures		(3,872)	(4,567)
Long-term investments and restricted long-term investments		(989)	(1,077)
Distributions from equity investments in excess of cumulative earnings		268	1,214
Additions to intangible assets		(81)	(458)
Affiliate loans, net		(232)	(50)
Proceeds from dispositions			1,913
Reimbursement of capital expenditures			0
Contributions to subsidiaries		0	0
Return of share capital from subsidiaries		0	0
Advances to affiliates		(56,349)	(3,380)
Repayment of advances to affiliates		12,367	2,290
Other			(12)
Net cash (used in)/provided by investing activities		(48,888)	(4,127)
Financing activities
Net change in short-term borrowings		245	(196)
Net change in commercial paper and credit facility draws		2,051	(1,545)
Debenture and term note issues, net of issue costs		2,553	981
Debenture and term note repayments		(355)	(2,604)
Sale of noncontrolling interests in subsidiaries			1,289
Contributions from noncontrolling interests		0	0
Distributions to noncontrolling interests		0	0
Contributions from redeemable noncontrolling interests		0	0
Distributions to redeemable noncontrolling interests		0	0
Contributions from parents		2,884	7,267
Distributions to parents		(7,821)	(5,914)
Redemption of preferred shares held by subsidiary (Note 10)		(300)
Common shares issued		0	0
Preference share dividends		0	0
Common share dividends		0	0
Advances from affiliates		49,624	6,236
Repayment of advances from affiliates		(6,359)	(9,180)
Other		(49)	4
Net cash provided by/(used in) financing activities		42,473	(3,662)
Effect of translation of foreign denominated cash and cash equivalents and restricted cash		(17)	23
Net increase/(decrease) in cash and cash equivalents and restricted cash		244	135
Cash and cash equivalents and restricted cash at beginning of period	612	612	571
Cash and cash equivalents and restricted cash at end of period		856	706
Spectra Energy Partners L P | Subsidiary Issuer and Guarantor - SEP and EEP | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in)/provided by operating activities		1,305	1,536
Investing activities
Capital expenditures		0	0
Long-term investments and restricted long-term investments		(10)	(12)
Distributions from equity investments in excess of cumulative earnings		17	29
Additions to intangible assets		0	0
Affiliate loans, net		0	0
Proceeds from dispositions			0
Reimbursement of capital expenditures			0
Contributions to subsidiaries		0	(78)
Return of share capital from subsidiaries		0	0
Advances to affiliates		0	0
Repayment of advances to affiliates		0	515
Other			0
Net cash (used in)/provided by investing activities		7	454
Financing activities
Net change in short-term borrowings		0	0
Net change in commercial paper and credit facility draws		(2,011)	(758)
Debenture and term note issues, net of issue costs		0	0
Debenture and term note repayments		0	(644)
Sale of noncontrolling interests in subsidiaries			0
Contributions from noncontrolling interests		0	0
Distributions to noncontrolling interests		0	0
Contributions from redeemable noncontrolling interests		0	0
Distributions to redeemable noncontrolling interests		0	0
Contributions from parents		0	0
Distributions to parents		(1,014)	(1,407)
Redemption of preferred shares held by subsidiary (Note 10)		0
Common shares issued		0	0
Preference share dividends		0	0
Common share dividends		0	0
Advances from affiliates		5,091	821
Repayment of advances from affiliates		(3,383)	0
Other		(5)	(6)
Net cash provided by/(used in) financing activities		(1,322)	(1,994)
Effect of translation of foreign denominated cash and cash equivalents and restricted cash		0	0
Net increase/(decrease) in cash and cash equivalents and restricted cash		(10)	(4)
Cash and cash equivalents and restricted cash at beginning of period	16	16	14
Cash and cash equivalents and restricted cash at end of period		6	10
Enbridge Energy Partners, L.P. | Subsidiary Issuer and Guarantor - SEP and EEP | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in)/provided by operating activities		1,027	(298)
Investing activities
Capital expenditures		0	0
Long-term investments and restricted long-term investments		0	0
Distributions from equity investments in excess of cumulative earnings		850	793
Additions to intangible assets		0	0
Affiliate loans, net		0	0
Proceeds from dispositions			0
Reimbursement of capital expenditures			0
Contributions to subsidiaries		(8)	(10)
Return of share capital from subsidiaries		0	0
Advances to affiliates		(2,088)	(1,206)
Repayment of advances to affiliates		501	1,270
Other			0
Net cash (used in)/provided by investing activities		(745)	847
Financing activities
Net change in short-term borrowings		0	0
Net change in commercial paper and credit facility draws		(1,017)	286
Debenture and term note issues, net of issue costs		0	0
Debenture and term note repayments		(1,189)	(509)
Sale of noncontrolling interests in subsidiaries			0
Contributions from noncontrolling interests		0	0
Distributions to noncontrolling interests		0	0
Contributions from redeemable noncontrolling interests		0	0
Distributions to redeemable noncontrolling interests		0	0
Contributions from parents		0	0
Distributions to parents		(489)	(499)
Redemption of preferred shares held by subsidiary (Note 10)		0
Common shares issued		0	0
Preference share dividends		0	0
Common share dividends		0	0
Advances from affiliates		4,341	2,024
Repayment of advances from affiliates		(1,921)	(1,847)
Other		(6)	(3)
Net cash provided by/(used in) financing activities		(281)	(548)
Effect of translation of foreign denominated cash and cash equivalents and restricted cash		0	0
Net increase/(decrease) in cash and cash equivalents and restricted cash		1	1
Cash and cash equivalents and restricted cash at beginning of period	$ 0	0	0
Cash and cash equivalents and restricted cash at end of period		$ 1	$ 1