Consolidated Statements of Income and Comprehensive Income (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenues
Total revenues	$ 2,996.6	$ 3,209.9	$ 3,363.5
Expenses
Fuel	694.7	731.4	748.9
Purchased power	105.3	125.9	179.6
Cost of natural gas sold	155.7	210.4	284.5
Other	462.5	436.9	492.9
Depreciation and amortization	330.6	317.2	305.6
Taxes, other than income	222.3	223.7	224.5
Total expenses	2,440.1	2,626.7	2,782.5
Income from operations	556.5	583.2	581.0
Other income
Allowance for other funds used during construction	2.6	1.0	1.9
Total other income	10.8	7.7	(44.3)
Interest charges
Interest on long-term debt	185.0	198.0	216.6
Allowance for borrowed funds used during construction	(1.5)	(0.6)	(1.1)
Total interest charges	183.5	197.4	215.5
Income before provision for income taxes	383.8	393.5	321.2
Provision for income taxes	137.8	142.7	109.6
Net income	212.7	272.6	239.0
Other comprehensive income, net of tax
Net unrealized (loss) gain on cash flow hedges	(4.2)	(0.8)	3.1
Other comprehensive (loss) income, net of tax	(9.0)	(4.8)	7.8
Comprehensive income	203.7	267.8	246.8
TAMPA ELECTRIC CO [Member]
Revenues
Electric (includes franchise fees and gross receipts taxes of $91.1 in 2012, $85.6 in 2011 and $89.8 in 2010)	1,981.0	2,020.1	2,162.8
Gas (includes franchise fees and gross receipts taxes of $20.4 in 2012, $23.7 in 2011 and $26.3 in 2010)	397.0	450.5	510.8
Total revenues	2,378.0	2,470.6	2,673.6
Expenses
Fuel	694.7	731.4	748.9
Purchased power	105.3	125.9	179.6
Cost of natural gas sold	155.8	210.4	284.5
Other	462.0	436.4	492.4
Depreciation and amortization	288.2	270.5	261.9
Taxes, other than income	184.0	179.7	183.9
Total expenses	1,890.0	1,954.3	2,151.2
Income from operations	488.0	516.3	522.4
Other income
Allowance for other funds used during construction	2.6	1.0	1.9
Other income, net	4.1	2.9	3.3
Total other income	6.7	3.9	5.2
Interest charges
Interest on long-term debt	119.6	128.6	130.9
Other interest	7.7	11.5	11.2
Allowance for borrowed funds used during construction	(1.5)	(0.6)	(1.1)
Total interest charges	125.8	139.5	141.0
Income before provision for income taxes	368.9	380.7	386.6
Provision for income taxes	141.7	145.4	143.7
Net income	227.2	235.3	242.9
Other comprehensive income, net of tax
Net unrealized (loss) gain on cash flow hedges	(4.1)	0.7	0.8
Other comprehensive (loss) income, net of tax	(4.1)	0.7	0.8
Comprehensive income	$ 223.1	$ 236.0	$ 243.7