Revenue - Summary of Disaggregates TEC Revenue by Major Source (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation Of Revenue [Line Items]
Total electric revenue	$ 2,170	$ 1,845	$ 1,961
Total gas revenue	525	427	443
Total revenue	2,695	2,272	2,404
Residential [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	1,156	1,018	1,046
Total gas revenue	212	158	154
Commercial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	602	506	562
Total gas revenue	191	135	146
Industrial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	172	133	156
Total gas revenue	25	23	21
Regulatory Deferrals and Unbilled Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	(8)	(25)	(49)
Other [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	248	213	246
Total gas revenue	97	111	122
Eliminations [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	(4)	(4)	(4)
Total gas revenue	(3)	(6)	(18)
Total revenue	(7)	(10)	(22)
Eliminations [Member] | Residential [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0	0
Total gas revenue	0	0	0
Eliminations [Member] | Commercial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0	0
Total gas revenue	0	0	0
Eliminations [Member] | Industrial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0	0
Total gas revenue	0	0	0
Eliminations [Member] | Regulatory Deferrals and Unbilled Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0	0
Eliminations [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	(4)	(4)	(4)
Total gas revenue	(3)	(6)	(18)
Tampa Electric [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	2,174	1,849	1,965
Total gas revenue	0	0	0
Total revenue	2,174	1,849	1,965
Tampa Electric [Member] | Residential [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	1,156	1,018	1,046
Total gas revenue	0	0	0
Tampa Electric [Member] | Commercial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	602	506	562
Total gas revenue	0	0	0
Tampa Electric [Member] | Industrial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	172	133	156
Total gas revenue	0	0	0
Tampa Electric [Member] | Regulatory Deferrals and Unbilled Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	(8)	(25)	(49)
Tampa Electric [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	252	217	250
Total gas revenue	0	0	0
PGS [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0	0
Total gas revenue	528	433	461
Total revenue	528	433	461
PGS [Member] | Residential [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0	0
Total gas revenue	212	158	154
PGS [Member] | Commercial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0	0
Total gas revenue	191	135	146
PGS [Member] | Industrial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0	0
Total gas revenue	25	23	21
PGS [Member] | Regulatory Deferrals and Unbilled Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0	0
PGS [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0	0
Total gas revenue	$ 100	$ 117	$ 140