Consolidated Statements of Capitalization - Long-Term Debt (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2024	Jan. 30, 2024	Dec. 31, 2023	Jul. 12, 2022
Debt Instrument [Line Items]
Stated interest rate		4.90%
Long-term debt, total	$ 3,975		$ 4,275
3.88% Notes [Member]
Debt Instrument [Line Items]
Stated interest rate	3.88%
Long-term debt, total	$ 0		300
4.90% Notes [Member]
Debt Instrument [Line Items]
Stated interest rate	4.90%
Long-term debt, total	$ 500		0
2.40% Notes [Member]
Debt Instrument [Line Items]
Stated interest rate	2.40%
Long-term debt, total	$ 400		400
6.55% Notes [Member]
Debt Instrument [Line Items]
Stated interest rate	6.55%
Long-term debt, total	$ 250		250
6.15% Notes [Member]
Debt Instrument [Line Items]
Stated interest rate	6.15%
Long-term debt, total	$ 250		250
4.10% Notes [Member]
Debt Instrument [Line Items]
Stated interest rate	4.10%
Long-term debt, total	$ 300		300
4.35% Notes [Member]
Debt Instrument [Line Items]
Stated interest rate	4.35%
Long-term debt, total	$ 300		300
4.20% Notes [Member]
Debt Instrument [Line Items]
Stated interest rate	4.20%
Long-term debt, total	$ 250		250
4.30% Notes [Member]
Debt Instrument [Line Items]
Stated interest rate	4.30%
Long-term debt, total	$ 350		350
4.45% Notes [Member]
Debt Instrument [Line Items]
Stated interest rate	4.45%
Long-term debt, total	$ 375		375
3.63% Notes [Member]
Debt Instrument [Line Items]
Stated interest rate	3.63%
Long-term debt, total	$ 300		300
3.45% Notes [Member]
Debt Instrument [Line Items]
Stated interest rate	3.45%
Long-term debt, total	$ 400		400
5.00% Notes [Member]
Debt Instrument [Line Items]
Stated interest rate	5.00%			5.00%
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