Non-Derivative Fair Value Measurements (Nonrecurring Fair Value Measurements) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2020	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-lived assets, carrying amount		$ 91,803	$ 111,059	$ 99,348
Impairment, Long-Lived Asset, Held-for-Use, Statement of Income or Comprehensive Income [Extensible Enumeration]		Income (Loss) from Equity Method Investments
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	$ 800	1,500
Impairment of long-lived assets, after tax	600	$ 1,200
Equity method investment write-off, carrying amount	600
Equity method investment, liability	$ 200