Revenue - Summary of Disaggregates TEC Revenue by Major Source (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Disaggregation Of Revenue [Line Items]
Total electric revenue	$ 2,526	$ 2,637	$ 2,519
Total gas revenue	0	0	650
Total revenue	2,526	2,637	3,169
Residential [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	1,507	1,711	1,381
Total gas revenue			229
Commercial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	686	803	666
Total gas revenue			200
Industrial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	162	203	176
Total gas revenue			31
Regulatory Deferrals [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	(116)	(387)	(21)
Unbilled Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	5	(2)	9
Other [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	282	309	308
Total gas revenue			190
Eliminations [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue			(4)
Total gas revenue			(6)
Total revenue			(10)
Eliminations [Member] | Residential [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue			0
Total gas revenue			0
Eliminations [Member] | Commercial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue			0
Total gas revenue			0
Eliminations [Member] | Industrial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue			0
Total gas revenue			0
Eliminations [Member] | Regulatory Deferrals [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue			0
Eliminations [Member] | Unbilled Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue			0
Eliminations [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue			(4)
Total gas revenue			(6)
Tampa Electric [Member] | Operating Segments [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue			2,523
Total gas revenue			0
Total revenue	2,526	2,637	2,523
Tampa Electric [Member] | Operating Segments [Member] | Residential [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	1,507	1,711	1,381
Total gas revenue			0
Tampa Electric [Member] | Operating Segments [Member] | Commercial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	686	803	666
Total gas revenue			0
Tampa Electric [Member] | Operating Segments [Member] | Industrial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	162	203	176
Total gas revenue			0
Tampa Electric [Member] | Operating Segments [Member] | Regulatory Deferrals [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	(116)	(387)	(21)
Tampa Electric [Member] | Operating Segments [Member] | Unbilled Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	5	(2)	9
Tampa Electric [Member] | Operating Segments [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	$ 282	$ 309	312
Total gas revenue			0
PGS [Member] | Operating Segments [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue			0
Total gas revenue			656
Total revenue			656
PGS [Member] | Operating Segments [Member] | Residential [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue			0
Total gas revenue			229
PGS [Member] | Operating Segments [Member] | Commercial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue			0
Total gas revenue			200
PGS [Member] | Operating Segments [Member] | Industrial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue			0
Total gas revenue			31
PGS [Member] | Operating Segments [Member] | Regulatory Deferrals [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue			0
PGS [Member] | Operating Segments [Member] | Unbilled Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue			0
PGS [Member] | Operating Segments [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue			0
Total gas revenue			$ 196