Issuances of Common Stock - Additional Information (Details) - USD ($) shares in Millions, $ in Millions	1 Months Ended	9 Months Ended
	Apr. 30, 2016	Sep. 30, 2016	Sep. 30, 2015	Mar. 01, 2016
Class of Stock [Line Items]
Spectra Energy common stock issued		$ 878	$ 2
SE Corp At-the-Market program
Class of Stock [Line Items]
Equity Distribution Agreement - Maximum Aggregate Offering Price				$ 500
Spectra Energy common stock issued, shares		12.9
Spectra Energy common stock issued		$ 383
Overnight equity offering
Class of Stock [Line Items]
Spectra Energy common stock issued, shares	16.1
Spectra Energy common stock issued	$ 479
Spectra Energy Partners, LP | Spectra Energy Corp | Limited Partner | Private Placement
Class of Stock [Line Items]
Spectra Energy purchase of SEP's common units	10.4