Consolidated Statements of Capitalization - Long-term Debt Maturities (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013
Debt Instrument [Line Items]
Total long-term debt maturities	$ 2,923.8
Tampa Electric Company [Member]
Debt Instrument [Line Items]
2014	83.3
2015	83.3
2016	83.4
2017	0
2018	254.2
Thereafter	1,146.7
Total long-term debt maturities	1,650.9
Long Term Debt Maturities [Member]
Debt Instrument [Line Items]
2014	83.3
2015	83.3
2016	83.4
2017	0
2018	304.2
Thereafter	1,328.4
Total long-term debt maturities	1,882.6
PGS [Member]
Debt Instrument [Line Items]
2014	0
2015	0
2016	0
2017	0
2018	50.0
Thereafter	181.7
Total long-term debt maturities	$ 231.7