Consolidated Statements of Capitalization - Long-Term Debt - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Long-term debt, total	$ 3,975	$ 4,275
Unamortized debt discount, net	(10)	(14)
Debt issuance costs	(30)	(28)
Total carrying amount of long-term debt	3,935	4,233
Less amount due within one year	0	300
Total long-term debt	3,935	3,933
Long-term debt, fair value	$ 3,431	3,831
3.88% Notes [Member]
Debt Instrument [Line Items]
Due	2024
Long-term debt, total	$ 0	300
4.90% Notes [Member]
Debt Instrument [Line Items]
Due	2029
Long-term debt, total	$ 500	0
2.40% Notes [Member]
Debt Instrument [Line Items]
Due	2031
Long-term debt, total	$ 400	400
6.55% Notes [Member]
Debt Instrument [Line Items]
Due	2036
Long-term debt, total	$ 250	250
6.15% Notes [Member]
Debt Instrument [Line Items]
Due	2037
Long-term debt, total	$ 250	250
4.10% Notes [Member]
Debt Instrument [Line Items]
Due	2042
Long-term debt, total	$ 300	300
4.35% Notes [Member]
Debt Instrument [Line Items]
Due	2044
Long-term debt, total	$ 300	300
4.20% Notes [Member]
Debt Instrument [Line Items]
Due	2045
Long-term debt, total	$ 250	250
4.30% Notes [Member]
Debt Instrument [Line Items]
Due	2048
Long-term debt, total	$ 350	350
4.45% Notes [Member]
Debt Instrument [Line Items]
Due	2049
Long-term debt, total	$ 375	375
3.63% Notes [Member]
Debt Instrument [Line Items]
Due	2050
Long-term debt, total	$ 300	300
3.45% Notes [Member]
Debt Instrument [Line Items]
Due	2051
Long-term debt, total	$ 400	400
5.00% Notes [Member]
Debt Instrument [Line Items]
Due	2052
Long-term debt, total	$ 300	300
LongTerm Debt Reclassification [Member]
Debt Instrument [Line Items]
Long-term debt, total	0	500
Tampa Electric [Member]
Debt Instrument [Line Items]
Long-term debt, total	$ 3,975	$ 3,775