Acquisitions (Details) $ in Millions			1 Months Ended
	Jul. 16, 2019 USD ($) mi	Jan. 01, 2019 USD ($) county customer mi MW	Dec. 31, 2018 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)
Business Acquisition [Line Items]
Goodwill				$ 4,213	$ 4,204
NextEra Energy Capital Holdings, Inc. (Consolidated) [Member] | Term Loan Agreements [Member]
Business Acquisition [Line Items]
Borrowings			$ 4,500
Trans Bay Cable, LLC [Member]
Business Acquisition [Line Items]
Number of miles of power lines | mi	53
Gulf Power [Member]
Business Acquisition [Line Items]
Cash purchase price		$ 4,440
Business combination, recognized identifiable assets acquired and liabilities assumed, noncurrent liabilities, long-term debt		1,300
Assets assumed		5,200
Property, plant and equipment		4,000
Regulatory assets		494
Assumed liabilities		3,400
Regulatory liabilities		635
Deferred income taxes		562
Goodwill		$ 2,700
Gulf Power [Member] | Gulf Power [Member]
Business Acquisition [Line Items]
Number of customers acquired (more than) | customer		470,000
Number of counties in which entity operates | county		8
Number of miles of power lines | mi		9,500
Electric generating facility capacity (in megawatts) | MW		2,300
Trans Bay Cable, LLC [Member]
Business Acquisition [Line Items]
Assets assumed	$ 703
Assumed liabilities	643
Goodwill	610
Goodwill, Expected Tax Deductible Amount				$ 572
Trans Bay Cable, LLC [Member] | NextEra Energy Transmission, LLC Subsidiary [Member]
Business Acquisition [Line Items]
Cash purchase price	670
Business combination, recognized identifiable assets acquired and liabilities assumed, noncurrent liabilities, long-term debt	$ 422