Related Party Transactions - Schedule of Related Parties (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Related Party Transaction [Line Items]
Natural gas purchases (net of sales) from affiliates	$ 21	$ 71	$ 57	$ 185
Services to/(from) affiliates	8	(1)	23	(4)
Interest expense to affiliates	61	44	180	117
Dividends to TECO Energy			302	348
Equity contributions from TECO Energy			300	470
Related Party [Member]
Related Party Transaction [Line Items]
Interest income from affiliates	10	0	28	0
Interest expense to affiliates	3	0	8	0
PGS [Member]
Related Party Transaction [Line Items]
Interest receivable from PGS	4		4		$ 0
PGS [Member] | Related Party [Member]
Related Party Transaction [Line Items]
Note receivable from PGS	889		889		0
Affiliate [Member]
Related Party Transaction [Line Items]
Accounts receivable excluding asset management agreements	11		11		5
Taxes receivable	0		0		10
Accounts payable	14		14		31
Note payable to TECO Energy	195		195		195
Interest payable to TECO Energy	1		1		0
Taxes payable	4		4		0
Emera Energy Services Inc [Member]
Related Party Transaction [Line Items]
Accounts receivable related to asset management agreements to Emera Energy Services Inc.	4		4		$ 7
TECO Energy [Member]
Related Party Transaction [Line Items]
Dividends to TECO Energy	132	146	302	348
Equity contributions from TECO Energy	$ 100	$ 190	$ 300	$ 470