Income Taxes - Narrative (Details) - USD ($) $ in Millions		12 Months Ended
	Nov. 01, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Components of Income Tax Expense (Benefit) [Line Items]
Long-term income tax receivable		$ 744	$ 658
Operating loss carryforwards		10,210
Goodwill		$ 11,650	11,506	$ 9,722
Years eligible for renewable energy production tax credit		10 years
Production tax credits		$ 1,400	$ 1,200	$ 800
Change in tax status		(2.00%)	0.00%	0.00%
Unrecognized tax benefits		$ 100	$ 141
Natural Gas Transmission and Storage
Components of Income Tax Expense (Benefit) [Line Items]
Goodwill	$ 1,741
Natural Gas Transmission and Storage | Goodwill
Components of Income Tax Expense (Benefit) [Line Items]
Useful life, intangible asset	15 years
United Kingdom
Components of Income Tax Expense (Benefit) [Line Items]
Change in enacted tax rate		$ 105	35
United Kingdom | Corporate tax rate, effective April 1, 2020
Components of Income Tax Expense (Benefit) [Line Items]
Change in tax status		19.00%
United Kingdom | Corporate tax rate, effective April 2023
Components of Income Tax Expense (Benefit) [Line Items]
Change in tax status		25.00%
United Kingdom | Corporate tax rate, effective April 1, 2020 further reduction
Components of Income Tax Expense (Benefit) [Line Items]
Change in tax status		17.00%
Domestic Tax Authority and State and Local Jurisdiction | Natural Gas Transmission and Storage
Components of Income Tax Expense (Benefit) [Line Items]
Goodwill	$ 900
State
Components of Income Tax Expense (Benefit) [Line Items]
Operating loss carryforwards		$ 9,013
State | Iowa Senate File 2417
Components of Income Tax Expense (Benefit) [Line Items]
Operating loss carryforwards		100	138
Parent Company
Components of Income Tax Expense (Benefit) [Line Items]
Income tax receivable (payable), related parties current		324	13
Long-term income tax receivable		$ 744	$ 658