Acquisitions and Dispositions - Direct Energy Purchase Price Allocation (Details) - USD ($) $ in Millions		12 Months Ended
	Jan. 05, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Other Assets
Goodwill		$ 1,650	$ 1,795	$ 579
Texas
Other Assets
Goodwill		710	716	289
East
Other Assets
Goodwill		$ 723	$ 853	$ 240
Customer Relationships
Other Liabilities
Weighted average useful life, years		6 years	12 years
Direct Energy
Current Assets
Cash and cash equivalents			$ 152
Funds deposited by counterparties			21
Restricted cash			9
Accounts receivable, net			1,802
Inventory			106
Derivative instruments			1,014
Cash collateral paid in support of energy risk management activities			233
Prepayments and other current assets			173
Total current assets			3,510
Property, plant and equipment, net			151
Other Assets
Goodwill			1,250
Intangible assets			2,321
Derivative instruments			531
Other non-current assets			31
Total other assets			4,133
Total Assets			7,794
Current Liabilities
Accounts payable			1,116
Derivative instruments			1,266
Cash collateral received in support of energy risk management activities			21
Accrued expenses and other current liabilities			670
Total current liabilities			3,073
Other Liabilities
Derivative instruments			562
Deferred income taxes			320
Other non-current liabilities			115
Total other liabilities			997
Total Liabilities			4,070
Direct Energy Purchase Price			3,724
Goodwill, expected to be tax deductible			322
Direct Energy | Texas
Other Assets
Goodwill			427
Direct Energy | East
Other Assets
Goodwill			648
Direct Energy | West/Services/Other
Other Assets
Goodwill			175
Direct Energy | Customer Relationships
Other Assets
Intangible assets			1,277
Other Liabilities
Weighted average useful life, years	12 years
Direct Energy | Customer and Supply Contracts
Other Assets
Intangible assets			610
Other Liabilities
Weighted average useful life, years	12 years
Direct Energy | Trade Names
Other Assets
Intangible assets			310
Other Liabilities
Weighted average useful life, years	12 years
Direct Energy | Renewables Energy Certificates
Other Assets
Intangible assets			$ 124
Other Liabilities
Weighted average useful life, years	12 years