Basis of Presentation - Narrative (Details) - USD ($) $ in Millions		1 Months Ended	9 Months Ended
	Jan. 01, 2019	Mar. 31, 2019	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Goodwill			$ 110		$ 110
ROU Assets			275		$ 0
Lease liabilities			306
Proceeds from issuance of preferred equity			97	$ 0
ASU 2016-02
Finite-Lived Intangible Assets [Line Items]
ROU Assets	$ 282
Lease liabilities	287
Deferred tax impact	$ 5
Noble Midstream
Finite-Lived Intangible Assets [Line Items]
Equity commitment		$ 200	$ 100
Proceeds from issuance of preferred equity		100
Issuance costs of preferred equity		$ 3
Annual dividend rate			6.50%
EPIC Crude Holdings, LP | Noble Midstream
Finite-Lived Intangible Assets [Line Items]
Step acquisition, percentage acquired			30.00%