Basis of Presentation - Narrative (Details) - USD ($) $ in Millions		1 Months Ended	6 Months Ended
	Jan. 01, 2019	Mar. 31, 2019	Jun. 30, 2019	Jun. 30, 2018	Mar. 25, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Goodwill			$ 110			$ 110
ROU Assets			272			$ 0
Lease liabilities			278
Proceeds from issuance of preferred equity			99	$ 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			$ 100		$ 200
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%