Severance Costs (Details) $ in Millions	3 Months Ended
	Sep. 30, 2020 USD ($)
Restructuring Cost and Reserve [Line Items]
Severance expense	$ 27
Payments of severance costs	11
General and Administrative Expense
Restructuring Cost and Reserve [Line Items]
Severance expense	6
Oil and Gas, Exploration and Production
Restructuring Cost and Reserve [Line Items]
Severance expense	1
Operating Expense
Restructuring Cost and Reserve [Line Items]
Severance expense	20
Severance
Restructuring Cost and Reserve [Line Items]
Expected remaining costs to be incurred	$ 16