Segment Information - Schedule of Segment Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 13, 2022
Segment Reporting Information [Line Items]
Total revenues	$ 3,169	$ 2,695	$ 2,272
Depreciation and amortization	436	430	384
Total interest charges	167	130	130
Provision for income taxes	121	80	82
Net income	540	446	424
Total assets	13,803	12,196	11,048	$ 13,803
Capital expenditures	1,427	1,397	1,361
Revenues - External [Member]
Segment Reporting Information [Line Items]
Total revenues	3,169	2,695	2,272
Sales to Affiliates [Member]
Segment Reporting Information [Line Items]
Sales to affiliates	0	0	0
Eliminations [Member]
Segment Reporting Information [Line Items]
Total revenues	(10)	(7)	(10)
Depreciation and amortization	0	0	0
Total interest charges	0	0	0
Provision for income taxes	0	0	0
Net income	0	0	0
Total assets		(663)	(653)	(732)
Capital expenditures	0	0	0
Eliminations [Member] | Revenues - External [Member]
Segment Reporting Information [Line Items]
Total revenues	0	0	0
Eliminations [Member] | Sales to Affiliates [Member]
Segment Reporting Information [Line Items]
Sales to affiliates	(10)	(7)	(10)
Tampa Electric [Member]
Segment Reporting Information [Line Items]
Total revenues	2,523	2,174	1,849
Tampa Electric [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenues	2,523	2,174	1,849
Depreciation and amortization	389	374	339
Total interest charges	142	110	113
Provision for income taxes	94	57	66
Net income	458	369	372
Total assets		10,650	9,800	12,064
Capital expenditures	1,099	1,081	1,028
Tampa Electric [Member] | Operating Segments [Member] | Revenues - External [Member]
Segment Reporting Information [Line Items]
Total revenues	2,519	2,170	1,845
Tampa Electric [Member] | Operating Segments [Member] | Sales to Affiliates [Member]
Segment Reporting Information [Line Items]
Sales to affiliates	4	4	4
PGS [Member]
Segment Reporting Information [Line Items]
Total revenues	656	528	433
PGS [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenues	656	528	433
Depreciation and amortization	47	56	45
Total interest charges	25	20	17
Provision for income taxes	27	23	16
Net income	82	77	52
Total assets		2,209	1,901	$ 2,471
Capital expenditures	328	316	333
PGS [Member] | Operating Segments [Member] | Revenues - External [Member]
Segment Reporting Information [Line Items]
Total revenues	650	525	427
PGS [Member] | Operating Segments [Member] | Sales to Affiliates [Member]
Segment Reporting Information [Line Items]
Sales to affiliates	$ 6	$ 3	$ 6