Non-Derivative Fair Value Measurements (Nonrecurring Fair Value Measurements) (Details) - USD ($) $ in Millions	2 Months Ended	12 Months Ended
	Feb. 17, 2022	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-lived assets, carrying amount		$ 91,803	$ 82,010	$ 99,348
Impairment of long-lived assets			72
Impairment of long-lived assets, after tax			$ 54
NEER [Member] | Mountain Valley Pipeline [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-lived assets, carrying amount		1,900
Fair value of long-lived assets		400
Impairment of long-lived assets		1,500
Impairment of long-lived assets, after tax		$ 1,200
NEER [Member] | Mountain Valley Pipeline [Member] | Subsequent Event
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of long-lived assets	$ 800
Impairment of long-lived assets, after tax	600
Equity method investment write-off, carrying amount	600
Equity method investment, liability	$ 200