Commitments and Contingencies (Schedule of Changes in Contract Obligations) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2019	Apr. 30, 2019	Dec. 31, 2018
Loss Contingency Accrual [Roll Forward]
Contractual Obligation	$ 468	$ 468		$ 111
Contract Obligation Accrual, Provision		400
Contractual Obligation, Settled		(51)
Contractual Obligation, Accretion of Discount		10
Contractual Obligation, Revision of Estimate	(2)
Divestitures Obligations, South Texas [Member]
Loss Contingency Accrual [Roll Forward]
Deficiency Fee Liability	(348)	(348)	$ 49
Sand Storage Deficiencies [Member]
Loss Contingency Accrual [Roll Forward]
Deficiency Fee Liability	(2)	(2)
Sand mine
Loss Contingency Accrual [Roll Forward]
Deficiency Fee Liability	$ (1)	$ (1)