Long Term Debt - Additional Information (Detail) (USD $)	2 Months Ended	12 Months Ended			2 Months Ended	9 Months Ended	12 Months Ended				12 Months Ended	11 Months Ended	9 Months Ended	5 Months Ended	3 Months Ended		9 Months Ended	48 Months Ended	65 Months Ended	12 Months Ended	3 Months Ended		8 Months Ended	48 Months Ended	65 Months Ended	0 Months Ended	9 Months Ended		12 Months Ended	9 Months Ended		3 Months Ended
	Mar. 01, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Mar. 01, 2011 Tampa Electric Company [Member]	Sep. 28, 2012 Tampa Electric Company [Member]	Dec. 31, 2013 Tampa Electric Company [Member]	Dec. 31, 2012 Tampa Electric Company [Member]	Dec. 31, 2011 Tampa Electric Company [Member]	Oct. 02, 2012 Tampa Electric Company [Member]	Dec. 19, 2012 San Jose [Member]	Dec. 05, 2012 6.75% Notes due 2015 [Member]	Sep. 28, 2012 2.6% Notes [Member] Tampa Electric Company [Member]	Jun. 05, 2012 4.1% Notes [Member] Tampa Electric Company [Member]	Mar. 15, 2012 HCIDA Pollution Control Revenue Refunding Bonds [Member]	Mar. 26, 2008 HCIDA Pollution Control Revenue Refunding Bonds [Member]	Sep. 03, 2013 HCIDA Pollution Control Revenue Refunding Bonds [Member]	Mar. 15, 2012 HCIDA Pollution Control Revenue Refunding Bonds [Member]	Sep. 01, 2013 HCIDA Pollution Control Revenue Refunding Bonds [Member]	Dec. 31, 2013 HCIDA Pollution Control Revenue Refunding Bonds [Member] Held Bonds [Member]	Mar. 15, 2012 HCIDA Pollution Control Revenue Refunding Bonds [Member] Tampa Electric Company [Member]	Mar. 26, 2008 HCIDA Pollution Control Revenue Refunding Bonds [Member] Tampa Electric Company [Member]	Sep. 03, 2013 HCIDA Pollution Control Revenue Refunding Bonds [Member] Tampa Electric Company [Member]	Mar. 15, 2012 HCIDA Pollution Control Revenue Refunding Bonds [Member] Tampa Electric Company [Member]	Sep. 01, 2013 HCIDA Pollution Control Revenue Refunding Bonds [Member] Tampa Electric Company [Member]	Oct. 02, 2012 HCIDA Pollution Control Revenue Refunding Bonds [Member] Tampa Electric Company [Member] 2013 [Member]	Oct. 02, 2012 HCIDA Pollution Control Revenue Refunding Bonds [Member] Tampa Electric Company [Member] 2013 [Member]	Oct. 02, 2012 HCIDA Pollution Control Revenue Refunding Bonds [Member] Tampa Electric Company [Member] 2023 [Member]	Dec. 31, 2013 HCIDA Pollution Control Revenue Refunding Bonds [Member] Tampa Electric Company [Member] Held Bonds [Member]	Oct. 02, 2012 HCIDA Pollution Control Revenue Refunding Bonds [Member] Five Point One Percentage Refunding Bonds [Member] Tampa Electric Company [Member] 2013 [Member]	Oct. 02, 2012 HCIDA Pollution Control Revenue Refunding Bonds [Member] Five Point Five Percentage Refunding Bonds [Member] Tampa Electric Company [Member] 2023 [Member]	Mar. 01, 2011 PCIDA Bonds [Member]	Mar. 01, 2011 PCIDA Bonds [Member] Tampa Electric Company [Member]
Debt Instrument [Line Items]
Long-term debt, carrying amount		$ 2,921,100,000	$ 2,972,700,000
Estimated fair value		3,184,100,000	3,442,200,000
Ownership of parent company		100.00%
Purchase in lieu of redemption	75,000,000	51,600,000	650,400,000	153,600,000	75,000,000		51,600,000	608,000,000	78,800,000		25,300,000				86,000,000	20,000,000	51,600,000			232,600,000	86,000,000	20,000,000	51,600,000						232,600,000	60,700,000	86,400,000
Interest at the initial term rate per annum													2.60%	4.10%				5.00%	5.15%					5.00%	5.15%		5.10%	5.50%				1.50%	1.50%
Principal amounts of notes redeemed										147,100,000		8,800,000
Redemption price of notes												1,141,860,000
Aggregate principal amount issued												1,000,000,000	250,000,000	300,000,000
Loss on debt extinguishment		0	(1,200,000)	0								1,200,000
Redeemable principal amount percentage																										100.00%
Issuance of notes, maturity year													Jan. 01, 2022	Jan. 01, 2042
Debt Instrument Principal amount Market Price Percentage													99.878%	99.724%
Proceeds from notes net of issuance													$ 247,700,000	$ 296,200,000
Libor interest rate						15								25