Basis of Presentation and Summary of Significant Accounting Policies - Property, Plant and Equipment, Net (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Buildings, machinery and equipment	$ 16,488	$ 16,510
Geothermal properties	1,595	1,553
Other	282	291
Property, plant and equipment, gross	18,365	18,354
Less: Accumulated depreciation	6,907	6,851
Property, plant and equipment, gross, less accumulated depreciation, depletion and amortization	11,458	11,503
Land	128	128
Construction in progress	351	332
Property, plant and equipment, net	$ 11,937	$ 11,963
Minimum [Member] | Building, Machinery and Equipment, Gross
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated useful lives	1 year 6 months
Minimum [Member] | Geothermal Properties, Gross
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated useful lives	13 years
Minimum [Member] | Property, Plant and Equipment, Other Types
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated useful lives	3 years
Maximum | Building, Machinery and Equipment, Gross
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated useful lives	50 years
Maximum | Geothermal Properties, Gross
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated useful lives	58 years
Maximum | Property, Plant and Equipment, Other Types
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated useful lives	50 years