Condensed Consolidating Financial Information Condensed Consolidating Balance Sheet (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2014
Current Assets
Cash and cash equivalents	$ 464	$ 213	$ 338	$ 215
Receivables-consolidated subsidiaries	0	0
Notes receivable-current-consolidated subsidiaries	0	0
Receivables-other	712	806
Other current assets	574	629
Total current assets	1,750	1,648
Noncurrent Assets
Investments in and loans to unconsolidated affiliates	2,742	2,592
Investments in consolidated subsidiaries	0	0
Advances receivable-consolidated subsidiaries	0	0
Notes receivable-consolidated subsidiaries	0	0
Goodwill	4,203	4,154
Other assets	401	310
Net property, plant and equipment	25,337	22,918
Regulatory assets and deferred debits	1,504	1,301
Total Assets	35,937	32,923
Current Liabilities
Accounts payable	736	511
Accounts payable-consolidated subsidiaries	0	0
Commercial paper	1,637	1,112
Short-term borrowings-consolidated subsidiaries	0	0
Taxes accrued	73	78
Current maturities of long-term debt	467	652
Other current liabilities	774	1,039
Total current liabilities	3,687	3,392
Noncurrent Liabilities
Long-term debt	13,094	12,892
Advances payable-consolidated subsidiaries	0	0
Notes payable-consolidated subsidiaries	0	0
Deferred credits and other liabilities	7,175	6,768
Preferred stock of subsidiaries	562	339
Equity
Controlling interests	7,468	6,526
Noncontrolling interests	3,951	3,006
Total equity	11,419	9,532	9,931	10,398
Total Liabilities and Equity	35,937	32,923
Eliminations
Current Assets
Cash and cash equivalents	0	0	0	0
Receivables-consolidated subsidiaries	(19)	(34)
Notes receivable-current-consolidated subsidiaries	(388)	(387)
Receivables-other	0	0
Other current assets	(5)	0
Total current assets	(412)	(421)
Noncurrent Assets
Investments in and loans to unconsolidated affiliates	0	0
Investments in consolidated subsidiaries	(35,296)	(33,080)
Advances receivable-consolidated subsidiaries	(6,613)	(6,599)
Notes receivable-consolidated subsidiaries	(2,800)	(2,800)
Goodwill	0	0
Other assets	0	0
Net property, plant and equipment	0	0
Regulatory assets and deferred debits	0	0
Total Assets	(45,121)	(42,900)
Current Liabilities
Accounts payable	0	0
Accounts payable-consolidated subsidiaries	(19)	(34)
Commercial paper	0	0
Short-term borrowings-consolidated subsidiaries	(388)	(387)
Taxes accrued	(5)	0
Current maturities of long-term debt	0	0
Other current liabilities	0	0
Total current liabilities	(412)	(421)
Noncurrent Liabilities
Long-term debt	0	0
Advances payable-consolidated subsidiaries	(6,613)	(6,599)
Notes payable-consolidated subsidiaries	(2,800)	(2,800)
Deferred credits and other liabilities	0	0
Preferred stock of subsidiaries	0	0
Equity
Controlling interests	(35,296)	(33,080)
Noncontrolling interests	0	0
Total equity	(35,296)	(33,080)
Total Liabilities and Equity	(45,121)	(42,900)
Spectra Energy Corp
Current Assets
Cash and cash equivalents	0	0	0	0
Receivables-consolidated subsidiaries	19	15
Notes receivable-current-consolidated subsidiaries	0	0
Receivables-other	0	2
Other current assets	16	25
Total current assets	35	42
Noncurrent Assets
Investments in and loans to unconsolidated affiliates	0	0
Investments in consolidated subsidiaries	14,844	13,919
Advances receivable-consolidated subsidiaries	0	0
Notes receivable-consolidated subsidiaries	0	0
Goodwill	0	0
Other assets	38	41
Net property, plant and equipment	0	0
Regulatory assets and deferred debits	4	3
Total Assets	14,921	14,005
Current Liabilities
Accounts payable	2	2
Accounts payable-consolidated subsidiaries	0	4
Commercial paper	0	0
Short-term borrowings-consolidated subsidiaries	0	0
Taxes accrued	0	5
Current maturities of long-term debt	0	0
Other current liabilities	78	102
Total current liabilities	80	113
Noncurrent Liabilities
Long-term debt	0	0
Advances payable-consolidated subsidiaries	6,613	6,599
Notes payable-consolidated subsidiaries	0	0
Deferred credits and other liabilities	760	767
Preferred stock of subsidiaries	0	0
Equity
Controlling interests	7,468	6,526
Noncontrolling interests	0	0
Total equity	7,468	6,526
Total Liabilities and Equity	14,921	14,005
Spectra Energy Capital, LLC
Current Assets
Cash and cash equivalents	1	1	1	1
Receivables-consolidated subsidiaries	0	6
Notes receivable-current-consolidated subsidiaries	0	0
Receivables-other	0	0
Other current assets	2	0
Total current assets	3	7
Noncurrent Assets
Investments in and loans to unconsolidated affiliates	0	0
Investments in consolidated subsidiaries	20,452	19,161
Advances receivable-consolidated subsidiaries	5,064	5,273
Notes receivable-consolidated subsidiaries	0	0
Goodwill	0	0
Other assets	31	27
Net property, plant and equipment	0	0
Regulatory assets and deferred debits	12	3
Total Assets	25,562	24,471
Current Liabilities
Accounts payable	3	3
Accounts payable-consolidated subsidiaries	19	28
Commercial paper	460	481
Short-term borrowings-consolidated subsidiaries	388	387
Taxes accrued	4	0
Current maturities of long-term debt	0	0
Other current liabilities	45	48
Total current liabilities	919	947
Noncurrent Liabilities
Long-term debt	2,903	2,891
Advances payable-consolidated subsidiaries	0	0
Notes payable-consolidated subsidiaries	2,800	2,800
Deferred credits and other liabilities	4,096	3,914
Preferred stock of subsidiaries	0	0
Equity
Controlling interests	14,844	13,919
Noncontrolling interests	0	0
Total equity	14,844	13,919
Total Liabilities and Equity	25,562	24,471
Non-Guarantor Subsidiaries
Current Assets
Cash and cash equivalents	463	212	$ 337	$ 214
Receivables-consolidated subsidiaries	0	13
Notes receivable-current-consolidated subsidiaries	388	387
Receivables-other	712	804
Other current assets	561	604
Total current assets	2,124	2,020
Noncurrent Assets
Investments in and loans to unconsolidated affiliates	2,742	2,592
Investments in consolidated subsidiaries	0	0
Advances receivable-consolidated subsidiaries	1,549	1,326
Notes receivable-consolidated subsidiaries	2,800	2,800
Goodwill	4,203	4,154
Other assets	332	242
Net property, plant and equipment	25,337	22,918
Regulatory assets and deferred debits	1,488	1,295
Total Assets	40,575	37,347
Current Liabilities
Accounts payable	731	506
Accounts payable-consolidated subsidiaries	0	2
Commercial paper	1,177	631
Short-term borrowings-consolidated subsidiaries	0	0
Taxes accrued	74	73
Current maturities of long-term debt	467	652
Other current liabilities	651	889
Total current liabilities	3,100	2,753
Noncurrent Liabilities
Long-term debt	10,191	10,001
Advances payable-consolidated subsidiaries	0	0
Notes payable-consolidated subsidiaries	0	0
Deferred credits and other liabilities	2,319	2,087
Preferred stock of subsidiaries	562	339
Equity
Controlling interests	20,452	19,161
Noncontrolling interests	3,951	3,006
Total equity	24,403	22,167
Total Liabilities and Equity	$ 40,575	$ 37,347