Debt (Details) - USD ($) | Nov. 01, 2016 | Jan. 06, 2016 | Sep. 30, 2016 | Sep. 30, 2015 | Sep. 30, 2016 | Sep. 30, 2015 | Dec. 31, 2015 | Sep. 20, 2016 | Aug. 27, 2015 |
Debt Instrument [Line Items] | | | | | | | | | | |
Debt | | | | $ 7,957,000,000 | | $ 7,957,000,000 | | $ 7,976,000,000 | | |
Unamortized Discount | | | | (23,000,000) | | (23,000,000) | | (24,000,000) | | |
Debt Instrument, Unamortized Premium | | | | 17,000,000 | | 17,000,000 | | 113,000,000 | | |
Total Debt, Net of Discount | | | | 7,915,000,000 | | 7,915,000,000 | | 8,029,000,000 | | |
Capital Lease Obligations, Current | | | | (61,000,000) | | (61,000,000) | | (53,000,000) | | |
Long-term Debt Due After One Year | | | | 7,854,000,000 | | 7,854,000,000 | | 7,976,000,000 | | |
Gain on tendered offers | [1] | | | 0 | $ 0 | 80,000,000 | $ 0 | | | |
Repayments of Long-term Lines of Credit | | | | | | 0 | $ 74,000,000 | | | |
Term Loan Facility [Member] | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Debt | | | | $ 1,400,000,000 | | $ 1,400,000,000 | | $ 0 | | |
Debt stated rate | | | | 1.698% | | 1.698% | | 0.00% | | |
Debt instrument, maturity date | | | | | | Jan. 6, 2019 | | | | |
Revolving Credit Facility, due August 27, 2020 | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Debt | | | | $ 0 | | $ 0 | | $ 0 | | |
Debt stated rate | | | | 0.00% | | 0.00% | | 0.00% | | |
Debt instrument, maturity date | | | | | | Aug. 27, 2020 | | Aug. 27, 2020 | | |
Maximum borrowing capacity | | | | $ 4,000,000,000 | | $ 4,000,000,000 | | | | |
Credit facility fee rate basis points, minimum | | | | | | | | | | 0.10% |
Credit facility fee rate basis points, maximum | | | | | | | | | | 0.25% |
Credit facility aggregate short-term loans and letters of credit, maximum | | | | | | | | | | $ 500,000,000 |
Credit facility aggregate short-term loans and letters of credit, committed | | | | 450,000,000 | | 450,000,000 | | | | |
Credit facility interest rate, Eurodollar rate plus, minimum | | | | | | | | | | 0.90% |
Credit facility interest rate, Eurodollar rate plus, maximum | | | | | | | | | | 1.50% |
Noble Midstream Revolving Credit Facility, due September 20, 2021 | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Debt | | | | $ 0 | | $ 0 | | $ 0 | | |
Debt stated rate | | | | 0.00% | | 0.00% | | 0.00% | | |
Capital Lease and Other Obligations | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Debt | | | | $ 368,000,000 | | $ 368,000,000 | | $ 403,000,000 | | |
Debt stated rate | | | | 0.00% | | 0.00% | | 0.00% | | |
Capital Lease Obligations, Current | | | | $ (61,000,000) | | $ (61,000,000) | | $ (53,000,000) | | |
8.25% Senior Notes, due March 1, 2019 | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Debt | | | | $ 1,000,000,000 | | $ 1,000,000,000 | | $ 1,000,000,000 | | |
Debt stated rate | | | | 8.25% | | 8.25% | | 8.25% | | |
Debt instrument, maturity date | | | | | | Mar. 1, 2019 | | Mar. 1, 2019 | | |
5.625% Senior Notes, due May 1, 2021 | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Debt | | | | $ 379,000,000 | | $ 379,000,000 | | $ 693,000,000 | | |
Debt stated rate | | | | 5.625% | | 5.625% | | 5.625% | | |
Debt instrument, maturity date | | | | | | May 1, 2021 | | May 1, 2021 | | |
4.15% Senior Notes, due December 15, 2021 | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Debt | | | | $ 1,000,000,000 | | $ 1,000,000,000 | | $ 1,000,000,000 | | |
Debt stated rate | | | | 4.15% | | 4.15% | | 4.15% | | |
Debt instrument, maturity date | | | | | | Dec. 15, 2021 | | Dec. 15, 2021 | | |
5.875% Senior Notes, due June 1, 2022 | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Debt | | | | $ 18,000,000 | | $ 18,000,000 | | $ 597,000,000 | | |
Debt stated rate | | | | 5.875% | | 5.875% | | 5.875% | | |
Debt instrument, maturity date | | | | | | Jun. 1, 2022 | | Jun. 1, 2022 | | |
7.25% Senior Notes, due October 15, 2023 | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Debt | | | | $ 100,000,000 | | $ 100,000,000 | | $ 100,000,000 | | |
Debt stated rate | | | | 7.25% | | 7.25% | | 7.25% | | |
Debt instrument, maturity date | | | | | | Oct. 15, 2023 | | Oct. 15, 2023 | | |
Unamortized Debt Issuance Expense | | | | $ (36,000,000) | | $ (36,000,000) | | $ (36,000,000) | | |
5.875% Senior Notes, due June 1, 2024 | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Debt | | | | $ 8,000,000 | | $ 8,000,000 | | $ 499,000,000 | | |
Debt stated rate | | | | 5.875% | | 5.875% | | 5.875% | | |
Debt instrument, maturity date | | | | | | Jun. 1, 2024 | | Jun. 1, 2024 | | |
3.90% Senior Notes, due November 15, 2024 | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Debt | | | | $ 650,000,000 | | $ 650,000,000 | | $ 650,000,000 | | |
Debt stated rate | | | | 3.90% | | 3.90% | | 3.90% | | |
Debt instrument, maturity date | | | | | | Nov. 15, 2024 | | Nov. 15, 2024 | | |
8.00% Senior Notes, due April 1, 2027 | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Debt | | | | $ 250,000,000 | | $ 250,000,000 | | $ 250,000,000 | | |
Debt stated rate | | | | 8.00% | | 8.00% | | 8.00% | | |
Debt instrument, maturity date | | | | | | Apr. 1, 2027 | | Apr. 1, 2027 | | |
6.00% Senior Notes, due March 1, 2041 | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Debt | | | | $ 850,000,000 | | $ 850,000,000 | | $ 850,000,000 | | |
Debt stated rate | | | | 6.00% | | 6.00% | | 6.00% | | |
Debt instrument, maturity date | | | | | | Mar. 1, 2041 | | Mar. 1, 2041 | | |
5.25% Senior Notes, due November 15, 2043 | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Debt | | | | $ 1,000,000,000 | | $ 1,000,000,000 | | $ 1,000,000,000 | | |
Debt stated rate | | | | 5.25% | | 5.25% | | 5.25% | | |
Debt instrument, maturity date | | | | | | Nov. 15, 2043 | | Nov. 15, 2043 | | |
5.05% Senior Notes, due November 15, 2044 | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Debt | | | | $ 850,000,000 | | $ 850,000,000 | | $ 850,000,000 | | |
Debt stated rate | | | | 5.05% | | 5.05% | | 5.05% | | |
Debt instrument, maturity date | | | | | | Nov. 15, 2044 | | Nov. 15, 2044 | | |
7.25% Senior Debentures, due August 1, 2097 | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Debt | | | | $ 84,000,000 | | $ 84,000,000 | | $ 84,000,000 | | |
Debt stated rate | | | | 7.25% | | 7.25% | | 7.25% | | |
Debt instrument, maturity date | | | | | | Aug. 1, 2097 | | Aug. 1, 2097 | | |
Revolving Credit Facility, due August 27, 2020 | Term Loan Facility [Member] | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Proceeds from Lines of Credit | | | | | | $ 1,380,000,000 | | | | |
Debt Instrument, Term | | | 3 years | | | | | | | |
Revolving Credit Facility, due August 27, 2020 | Credit Facility [Member] | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Credit facility fee rate basis points, minimum | | | 0.10% | | | | | | | |
Credit facility fee rate basis points, maximum | | | 0.75% | | | | | | | |
Revolving Credit Facility, due August 27, 2020 | Federal Funds Effective Swap Rate [Member] | Term Loan Facility [Member] | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Debt instrument, variable rate | | | 0.50% | | | | | | | |
Revolving Credit Facility, due August 27, 2020 | London Interbank Offered Rate (LIBOR) [Member] | Term Loan Facility [Member] | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Debt instrument, variable rate | | | 1.00% | | | | | | | |
Revolving Credit Facility, due August 27, 2020 | London Interbank Offered Rate (LIBOR) [Member] | Credit Facility [Member] | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Credit facility interest rate, Eurodollar rate plus, minimum | | | 1.00% | | | | | | | |
Credit facility interest rate, Eurodollar rate plus, maximum | | | 1.75% | | | | | | | |
Other Operating Income (Expense) [Member] | Revolving Credit Facility, due August 27, 2020 | Credit Facility [Member] | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Gain on tendered offers | | | | | | $ 80,000,000 | | | | |
Noble Midstream | Revolving Credit Facility, due August 27, 2020 | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Maximum borrowing capacity | | | | | | | | | $ 350,000,000 | |
Available increase in capacity | | | | | | | | | 350,000,000 | |
Debt Instrument, Term | | | | | | 5 years | | | | |
Noble Midstream | Revolving Credit Facility, due August 27, 2020 | Federal Funds Effective Swap Rate [Member] | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Debt instrument, variable rate | | | | | | 0.50% | | | | |
Noble Midstream | Revolving Credit Facility, due August 27, 2020 | London Interbank Offered Rate (LIBOR) [Member] | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Debt instrument, variable rate | | | | | | 1.00% | | | | |
Letter of Credit | Noble Midstream | Revolving Credit Facility, due August 27, 2020 | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Maximum borrowing capacity | | | | | | | | | $ 100,000,000 | |
Subsequent Event [Member] | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | |
Repayments of Long-term Lines of Credit | | $ 850,000,000 | | | | | | | | |
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[1] | Amount relates to the tendering of senior notes assumed in the Rosetta Merger. See Note 7. Debt. | |