Derivative Instruments (Significant Unobservable Inputs) (Details) - Level 3 | 6 Months Ended |
Jun. 30, 2022 USD ($) |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Assets, Fair Value Disclosure | $ 2,287,000,000 |
Financial and Nonfinancial Liabilities, Fair Value Disclosure | (3,881,000,000) |
Forward Contracts - Power [Member] | Forward Contracts - Power [Member] | Forward Price [Member] | Maximum | Discounted Cash Flow Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Forward price (in dollars per energy unit) | 266 |
Forward Contracts - Power [Member] | Forward Contracts - Power [Member] | Forward Price [Member] | Minimum | Discounted Cash Flow Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Forward price (in dollars per energy unit) | (3) |
Forward Contracts - Power [Member] | Forward Contracts - Power [Member] | Forward Price [Member] | Weighted Average [Member] | Discounted Cash Flow Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Forward price (in dollars per energy unit) | 48 |
Forward Contracts - Power [Member] | Derivative Financial Instruments, Assets [Member] | Forward Contracts - Power [Member] | Discounted Cash Flow Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Assets, Fair Value Disclosure | 294,000,000 |
Forward contracts - Gas [Member] | Forward contracts - Gas [Member] | Forward Price [Member] | Maximum | Discounted Cash Flow Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Forward price (in dollars per energy unit) | 26 |
Forward contracts - Gas [Member] | Forward contracts - Gas [Member] | Forward Price [Member] | Minimum | Discounted Cash Flow Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Forward price (in dollars per energy unit) | 2 |
Forward contracts - Gas [Member] | Forward contracts - Gas [Member] | Forward Price [Member] | Weighted Average [Member] | Discounted Cash Flow Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Forward price (in dollars per energy unit) | 5 |
Forward contracts - Gas [Member] | Derivative Financial Instruments, Assets [Member] | Forward contracts - Gas [Member] | Discounted Cash Flow Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Assets, Fair Value Disclosure | 352,000,000 |
Forward contracts - Congestion [Member] | Forward contracts - Congestion [Member] | Forward Price [Member] | Maximum | Discounted Cash Flow Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Forward price (in dollars per energy unit) | 23 |
Forward contracts - Congestion [Member] | Forward contracts - Congestion [Member] | Forward Price [Member] | Minimum | Discounted Cash Flow Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Forward price (in dollars per energy unit) | (37) |
Forward contracts - Congestion [Member] | Forward contracts - Congestion [Member] | Forward Price [Member] | Weighted Average [Member] | Discounted Cash Flow Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Forward price (in dollars per energy unit) | 0 |
Forward contracts - Congestion [Member] | Derivative Financial Instruments, Assets [Member] | Forward contracts - Congestion [Member] | Discounted Cash Flow Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Assets, Fair Value Disclosure | $ 36,000,000 |
Option Contracts, Power [Member] | Option Contracts, Power [Member] | Implied Correlations [Member] | Maximum | Option Models [Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Fair Value Inputs, Expected Rates | 88% |
Option Contracts, Power [Member] | Option Contracts, Power [Member] | Implied Correlations [Member] | Minimum | Option Models [Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Fair Value Inputs, Expected Rates | 37% |
Option Contracts, Power [Member] | Option Contracts, Power [Member] | Implied Correlations [Member] | Weighted Average [Member] | Option Models [Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Fair Value Inputs, Expected Rates | 53% |
Option Contracts, Power [Member] | Option Contracts, Power [Member] | Implied Volatilities [Member] | Maximum | Option Models [Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Fair Value Inputs, Expected Rates | 345% |
Option Contracts, Power [Member] | Option Contracts, Power [Member] | Implied Volatilities [Member] | Minimum | Option Models [Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Fair Value Inputs, Expected Rates | 20% |
Option Contracts, Power [Member] | Option Contracts, Power [Member] | Implied Volatilities [Member] | Weighted Average [Member] | Option Models [Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Fair Value Inputs, Expected Rates | 90% |
Option Contracts, Power [Member] | Derivative Financial Instruments, Assets [Member] | Option Contracts, Power [Member] | Option Models [Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Assets, Fair Value Disclosure | $ 134,000,000 |
Option Contracts, Primarily Gas [Member] | Option Contracts, Gas [Member] | Implied Correlations [Member] | Maximum | Option Models [Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Fair Value Inputs, Expected Rates | 88% |
Option Contracts, Primarily Gas [Member] | Option Contracts, Gas [Member] | Implied Correlations [Member] | Minimum | Option Models [Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Fair Value Inputs, Expected Rates | 37% |
Option Contracts, Primarily Gas [Member] | Option Contracts, Gas [Member] | Implied Correlations [Member] | Weighted Average [Member] | Option Models [Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Fair Value Inputs, Expected Rates | 53% |
Option Contracts, Primarily Gas [Member] | Option Contracts, Gas [Member] | Implied Volatilities [Member] | Maximum | Option Models [Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Fair Value Inputs, Expected Rates | 215% |
Option Contracts, Primarily Gas [Member] | Option Contracts, Gas [Member] | Implied Volatilities [Member] | Minimum | Option Models [Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Fair Value Inputs, Expected Rates | 20% |
Option Contracts, Primarily Gas [Member] | Option Contracts, Gas [Member] | Implied Volatilities [Member] | Weighted Average [Member] | Option Models [Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Fair Value Inputs, Expected Rates | 48% |
Option Contracts, Primarily Gas [Member] | Derivative Financial Instruments, Assets [Member] | Option Contracts, Gas [Member] | Option Models [Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Assets, Fair Value Disclosure | $ 1,148,000,000 |
Full Requirements and Unit Contingent Contracts [Member] | Full Requirements and Unit Contingent Contracts [Member] | Forward Price [Member] | Maximum | Discounted Cash Flow Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Forward price (in dollars per energy unit) | 605 |
Full Requirements and Unit Contingent Contracts [Member] | Full Requirements and Unit Contingent Contracts [Member] | Forward Price [Member] | Minimum | Discounted Cash Flow Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Forward price (in dollars per energy unit) | 10 |
Full Requirements and Unit Contingent Contracts [Member] | Full Requirements and Unit Contingent Contracts [Member] | Forward Price [Member] | Weighted Average [Member] | Discounted Cash Flow Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Forward price (in dollars per energy unit) | $ 92 |
Full Requirements and Unit Contingent Contracts [Member] | Full Requirements and Unit Contingent Contracts [Member] | Customer Migration Rate [Member] | Maximum | Discounted Cash Flow Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Fair Value Inputs, Expected Rates | 15% |
Full Requirements and Unit Contingent Contracts [Member] | Full Requirements and Unit Contingent Contracts [Member] | Customer Migration Rate [Member] | Minimum | Discounted Cash Flow Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Fair Value Inputs, Expected Rates | 0% |
Full Requirements and Unit Contingent Contracts [Member] | Full Requirements and Unit Contingent Contracts [Member] | Customer Migration Rate [Member] | Weighted Average [Member] | Discounted Cash Flow Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Fair Value Inputs, Expected Rates | 2% |
Full Requirements and Unit Contingent Contracts [Member] | Derivative Financial Instruments, Assets [Member] | Full Requirements and Unit Contingent Contracts [Member] | Discounted Cash Flow Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Assets, Fair Value Disclosure | $ 102,000,000 |
Forward contracts - Other [Member] [Member] | Derivative Financial Instruments, Assets [Member] | Forward contracts - Other [Member] [Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Assets, Fair Value Disclosure | 221,000,000 |
Derivative Financial Instruments, Liabilities [Member] | Forward Contracts - Power [Member] | Forward Contracts - Power [Member] | Discounted Cash Flow Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Financial and Nonfinancial Liabilities, Fair Value Disclosure | (591,000,000) |
Derivative Financial Instruments, Liabilities [Member] | Forward contracts - Gas [Member] | Forward contracts - Gas [Member] | Discounted Cash Flow Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Financial and Nonfinancial Liabilities, Fair Value Disclosure | (216,000,000) |
Derivative Financial Instruments, Liabilities [Member] | Forward contracts - Congestion [Member] | Forward contracts - Congestion [Member] | Discounted Cash Flow Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Financial and Nonfinancial Liabilities, Fair Value Disclosure | (12,000,000) |
Derivative Financial Instruments, Liabilities [Member] | Option Contracts, Power [Member] | Option Contracts, Power [Member] | Option Models [Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Financial and Nonfinancial Liabilities, Fair Value Disclosure | (28,000,000) |
Derivative Financial Instruments, Liabilities [Member] | Option Contracts, Primarily Gas [Member] | Option Contracts, Gas [Member] | Option Models [Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Financial and Nonfinancial Liabilities, Fair Value Disclosure | (1,022,000,000) |
Derivative Financial Instruments, Liabilities [Member] | Full Requirements and Unit Contingent Contracts [Member] | Full Requirements and Unit Contingent Contracts [Member] | Discounted Cash Flow Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Financial and Nonfinancial Liabilities, Fair Value Disclosure | (1,603,000,000) |
Derivative Financial Instruments, Liabilities [Member] | Forward contracts - Other [Member] [Member] | Forward contracts - Other [Member] [Member] | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Financial and Nonfinancial Liabilities, Fair Value Disclosure | $ (409,000,000) |