Condensed Consolidating Financial Information Condensed Consolidating Statements of Operations (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Condensed Financial Statements, Captions [Line Items]
Total operating revenues	$ 1,075	$ 1,103	$ 3,618	$ 3,918
Total operating expenses	754	714	2,432	2,582
Operating Income	321	389	1,186	1,336
Earnings (loss) from equity investments	51	48	100	(117)
Equity in earnings of consolidated subsidiaries	0	0	0	0
Other income and expenses, net	52	31	123	73
Interest expense	133	155	437	480
Earnings Before Income Taxes	291	313	972	812
Income Tax Expense (Benefit)	10	70	160	164
Net Income	281	243	812	648
Net Income—Noncontrolling Interests	86	69	234	189
Net Income—Controlling Interests	195	174	578	459
Eliminations
Condensed Financial Statements, Captions [Line Items]
Total operating revenues	(1)	(2)	(2)	(3)
Total operating expenses	(1)	(2)	(2)	(3)
Operating Income	0	0	0	0
Earnings (loss) from equity investments	0	0	0	0
Equity in earnings of consolidated subsidiaries	(465)	(477)	(1,489)	(1,235)
Other income and expenses, net	0	0	0	0
Interest expense	0	0	0	0
Earnings Before Income Taxes	(465)	(477)	(1,489)	(1,235)
Income Tax Expense (Benefit)	0	0	0	0
Net Income	(465)	(477)	(1,489)	(1,235)
Net Income—Noncontrolling Interests	0	0	0	0
Net Income—Controlling Interests	(465)	(477)	(1,489)	(1,235)
Spectra Energy Corp
Condensed Financial Statements, Captions [Line Items]
Total operating revenues	0	0	0	0
Total operating expenses	(5)	2	0	5
Operating Income	5	(2)	0	(5)
Earnings (loss) from equity investments	0	0	0	0
Equity in earnings of consolidated subsidiaries	193	170	564	445
Other income and expenses, net	0	0	(2)	0
Interest expense	0	0	0	0
Earnings Before Income Taxes	198	168	562	440
Income Tax Expense (Benefit)	3	(6)	(16)	(19)
Net Income	195	174	578	459
Net Income—Noncontrolling Interests	0	0	0	0
Net Income—Controlling Interests	195	174	578	459
Spectra Energy Capital, LLC
Condensed Financial Statements, Captions [Line Items]
Total operating revenues	0	0	0	0
Total operating expenses	1	(1)	3	(2)
Operating Income	(1)	1	(3)	2
Earnings (loss) from equity investments	0	0	0	0
Equity in earnings of consolidated subsidiaries	272	307	925	790
Other income and expenses, net	0	(1)	0	(1)
Interest expense	47	61	170	183
Earnings Before Income Taxes	224	246	752	608
Income Tax Expense (Benefit)	31	76	188	163
Net Income	193	170	564	445
Net Income—Noncontrolling Interests	0	0	0	0
Net Income—Controlling Interests	193	170	564	445
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Total operating revenues	1,076	1,105	3,620	3,921
Total operating expenses	759	715	2,431	2,582
Operating Income	317	390	1,189	1,339
Earnings (loss) from equity investments	51	48	100	(117)
Equity in earnings of consolidated subsidiaries	0	0	0	0
Other income and expenses, net	52	32	125	74
Interest expense	86	94	267	297
Earnings Before Income Taxes	334	376	1,147	999
Income Tax Expense (Benefit)	(24)	0	(12)	20
Net Income	358	376	1,159	979
Net Income—Noncontrolling Interests	86	69	234	189
Net Income—Controlling Interests	$ 272	$ 307	$ 925	$ 790