Debt - Narrative (Details) - Subsequent Event - NEER Segment	Jul. 15, 2021 USD ($)
Senior Secured Limited Resource Notes Maturing in August 2038 | Florida Pipeline Holdings LLC
Debt Instrument [Line Items]
Security interest (as a percent)	100.00%
Senior Secured Limited Resource Notes Maturing in August 2038 | Florida Southeast Connection
Debt Instrument [Line Items]
Security interest (as a percent)	100.00%
Senior Secured Limited Resource Notes Maturing in August 2038 | Sabal Trail Transmission
Debt Instrument [Line Items]
Security interest (as a percent)	42.50%
Senior Secured Limited Resource Notes Maturing in August 2038 | Florida Pipeline Holdings LLC
Debt Instrument [Line Items]
Principal amount	$ 1,513,000,000
Interest rate (as a percent)	2.92%
Senior Secured Limited Resource Notes Maturing in May 2028 | Florida Pipeline Funding LLC
Debt Instrument [Line Items]
Security interest (as a percent)	100.00%
Senior Secured Limited Resource Notes Maturing in May 2028 | Florida Pipeline Funding LLC
Debt Instrument [Line Items]
Principal amount	$ 260,000,000
Interest rate (as a percent)	4.70%