Acquisitions (Details) $ in Millions	3 Months Ended
	Mar. 31, 2021 USD ($) utlity state mi	Sep. 30, 2021 USD ($)	Jan. 01, 2021 USD ($)	Dec. 31, 2020 USD ($)
Business Acquisition [Line Items]
Carrying amount of assets, consolidated variable interest entity		$ 139,163		$ 127,684
Goodwill		4,844		$ 4,254
FPL
Business Acquisition [Line Items]
Carrying amount of assets, consolidated variable interest entity			$ 6,700
Property, plant and equipment			4,900
Regulatory assets			1,200
Assumed liabilities			3,900
Business combination, recognized identifiable assets acquired and liabilities assumed, noncurrent liabilities, long-term debt			1,800
Deferred income taxes			729
Regulatory liabilities			566
Goodwill			$ 2,700
GridLiance [Member] | NextEra Energy Transmission, LLC Subsidiary [Member]
Business Acquisition [Line Items]
Assumed liabilities		210
Goodwill		592
Number of FERC-r transmission utilities | utlity	3
Number of miles of power lines | mi	700
Number of states in which entity operates | state	6
Debt assumed	$ 175
Assets assumed		384
Goodwill, Expected Tax Deductible Amount		$ 586
Contingent consideration liabilities	264
Cash purchase price	$ 502
GridLiance [Member] | NextEra Energy Transmission, LLC Subsidiary [Member] | Midwest And Nevada [Member]
Business Acquisition [Line Items]
Number of states in which entity operates | state	5