Revenue - Summary of Disaggregates TEC Revenue by Major Source (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Disaggregation Of Revenue [Line Items]
Total electric revenue	$ 662	$ 531	$ 1,171	$ 977
Total gas revenue	159	123	341	276
Total revenue	821	654	1,512	1,253
Residential [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	348	276	618	508
Total gas revenue	50	49	125	116
Commercial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	170	144	307	270
Total gas revenue	49	46	105	99
Industrial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	47	41	84	78
Total gas revenue	8	6	15	12
Regulatory Deferrals and Unbilled Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	16	11	19	9
Other [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	81	59	143	112
Total gas revenue	52	22	96	49
Tampa Electric [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	663	532	1,173	979
Total gas revenue	0	0	0	0
Total revenue	663	532	1,173	979
Tampa Electric [Member] | Residential [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	348	276	618	508
Total gas revenue	0	0	0	0
Tampa Electric [Member] | Commercial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	170	144	307	270
Total gas revenue	0	0	0	0
Tampa Electric [Member] | Industrial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	47	41	84	78
Total gas revenue	0	0	0	0
Tampa Electric [Member] | Regulatory Deferrals and Unbilled Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	16	11	19	9
Tampa Electric [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	82	60	145	114
Total gas revenue	0	0	0	0
PGS [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0	0	0
Total gas revenue	160	123	343	278
Total revenue	160	123	343	278
PGS [Member] | Residential [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0	0	0
Total gas revenue	50	49	125	116
PGS [Member] | Commercial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0	0	0
Total gas revenue	49	46	105	99
PGS [Member] | Industrial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0	0	0
Total gas revenue	8	6	15	12
PGS [Member] | Regulatory Deferrals and Unbilled Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0	0	0
PGS [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0	0	0
Total gas revenue	53	22	98
Total revenue				51
Operating Segments [Member] | Tampa Electric [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	663	532	1,173	979
Operating Segments [Member] | PGS [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	160	123	343	278
Eliminations [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	(1)	(1)	(2)	(2)
Total gas revenue	(1)	0	(2)	(2)
Total revenue	(2)	(1)	(4)	(4)
Eliminations [Member] | Residential [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0		0	0
Total gas revenue	0	0	0	0
Eliminations [Member] | Commercial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0	0	0
Total gas revenue	0	0	0	0
Eliminations [Member] | Industrial [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0	0	0
Total gas revenue	0	0	0	0
Eliminations [Member] | Regulatory Deferrals and Unbilled Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	0	0	0	0
Eliminations [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue	(1)	(1)	(2)	(2)
Total gas revenue	$ (1)	0	$ (2)	$ (2)
Eliminations [Member] | Tampa Electric [Member] | Residential [Member]
Disaggregation Of Revenue [Line Items]
Total electric revenue		$ 0