Condensed Consolidating Financial Information Condensed Consolidating Statements of Comprehensive Income (Detail) - 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]
Net Income	$ 281	$ 243	$ 812	$ 648
Other comprehensive income (loss)	(75)	(343)	287	(735)
Total Comprehensive Income (Loss), net of tax	206	(100)	1,099	(87)
Less: Comprehensive Income—Noncontrolling Interests	84	64	239	178
Comprehensive Income (Loss)—Controlling Interests	122	(164)	860	(265)
Eliminations
Condensed Financial Statements, Captions [Line Items]
Net Income	(465)	(477)	(1,489)	(1,235)
Other comprehensive income (loss)	0	0	0	0
Total Comprehensive Income (Loss), net of tax	(465)	(477)	(1,489)	(1,235)
Less: Comprehensive Income—Noncontrolling Interests	0	0	0	0
Comprehensive Income (Loss)—Controlling Interests	(465)	(477)	(1,489)	(1,235)
Spectra Energy Corp
Condensed Financial Statements, Captions [Line Items]
Net Income	195	174	578	459
Other comprehensive income (loss)	2	2	4	5
Total Comprehensive Income (Loss), net of tax	197	176	582	464
Less: Comprehensive Income—Noncontrolling Interests	0	0	0	0
Comprehensive Income (Loss)—Controlling Interests	197	176	582	464
Spectra Energy Capital, LLC
Condensed Financial Statements, Captions [Line Items]
Net Income	193	170	564	445
Other comprehensive income (loss)	0	1	0	1
Total Comprehensive Income (Loss), net of tax	193	171	564	446
Less: Comprehensive Income—Noncontrolling Interests	0	0	0	0
Comprehensive Income (Loss)—Controlling Interests	193	171	564	446
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net Income	358	376	1,159	979
Other comprehensive income (loss)	(77)	(346)	283	(741)
Total Comprehensive Income (Loss), net of tax	281	30	1,442	238
Less: Comprehensive Income—Noncontrolling Interests	84	64	239	178
Comprehensive Income (Loss)—Controlling Interests	$ 197	$ (34)	$ 1,203	$ 60