Agreement to Acquire Noble Energy, Inc. (Details) $ in Billions	3 Months Ended
	Dec. 31, 2020 USD ($)	Jul. 20, 2020	Mar. 31, 2020 USD ($)
Noble Energy, Inc.
Subsequent Event [Line Items]
Long-term debt, net carrying value			$ 8.7
Subsequent Event | Noble Energy, Inc.
Subsequent Event [Line Items]
Conversion ratio of outstanding shares		0.1191
Forecast | Noble Energy, Inc.
Subsequent Event [Line Items]
Consideration transferred	$ 5.0