Basis of Presentation - Narrative (Details) - USD ($) $ in Millions			1 Months Ended	3 Months Ended
	Mar. 25, 2019	Jan. 01, 2019	Mar. 31, 2019	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Goodwill			$ 110	$ 110		$ 110
Share purchase plan, authorized amount			750	750
Proceeds from issuance of preferred equity				99	$ 0
Issuance costs of preferred equity			3
ROU Assets			273	273		$ 0
Lease liabilities			$ 280	$ 280
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
Proceeds from issuance of preferred equity	100
Issuance costs of preferred equity	$ 3