Consolidated Condensed Balance Sheets (Unaudited) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Current assets
Cash and cash equivalents	$ 167.0	$ 185.2
Receivables, less allowance for uncollectibles	323.8	287.2
Inventories, at average cost
Derivative assets	8.2	9.7
Regulatory assets	33.7	34.3
Deferred income taxes	87.7	100.3
Prepayments and other current assets	47.5	34.9
Income tax receivables	0.8	1.5
Total current assets	889.5	857.7
Property, plant and equipment
Construction work in progress	494.9	386.7
Other property	441.5	448.3
Property, plant and equipment, at original costs	9,202.5	9,077.3
Accumulated depreciation	(2,878.4)	(2,907.2)
Total property, plant and equipment, net	6,324.1	6,170.1
Other assets
Regulatory assets	283.9	293.1
Derivative assets	0.5	0.3
Deferred charges and other assets	122.8	126.8
Total other assets	407.2	420.2
Total assets	7,620.8	7,448.0
Current liabilities
Long-term debt due within one year	274.5	83.3
Notes payable	0	84.0
Accounts payable	232.3	261.7
Customer deposits	167.5	164.5
Regulatory liabilities	65.7	85.8
Derivative liabilities	0.2	0.1
Interest accrued	34.4	31.9
Taxes accrued	68.2	34.6
Other	18.4	19.5
Total current liabilities	861.2	765.4
Other liabilities
Deferred income taxes	497.4	444.0
Investment tax credits	9.2	9.4
Regulatory liabilities	621.4	631.4
Derivative liabilities	0.1	0.2
Deferred credits and other liabilities	422.0	426.1
Long-term debt, less amount due within one year	2,863.1	2,837.8
Total other liabilities	4,413.2	4,348.9
Commitments and contingencies (see Note 10)
Capital
Common equity	217.8	217.3
Additional paid in capital	1,587.8	1,581.3
Retained earnings	560.9	548.3
Accumulated other comprehensive loss	(20.1)	(13.2)
Total capital	2,346.4	2,333.7
Total liabilities and capital	7,620.8	7,448.0
Fuel [Member]
Inventories, at average cost
Utility inventories	137.4	118.7
Materials and supplies [Member]
Inventories, at average cost
Utility inventories	83.4	85.9
Electric [Member]
Property, plant and equipment
Public utilities, property, plant and equipment	6,941.7	6,934.0
Gas [Member]
Property, plant and equipment
Public utilities, property, plant and equipment	1,324.4	1,308.3
Tampa Electric Company [Member]
Current assets
Cash and cash equivalents	55.2	9.8
Receivables, less allowance for uncollectibles	256.7	227.6
Inventories, at average cost
Derivative assets	8.1	9.5
Regulatory assets	33.7	34.3
Deferred income taxes	20.4	29.4
Prepayments and other current assets	21.2	12.5
Income tax receivables	0	54.9
Total current assets	568.4	548.5
Property, plant and equipment
Construction work in progress	493.4	385.3
Property, plant and equipment, at original costs	8,700.7	8,568.8
Accumulated depreciation	(2,530.9)	(2,562.6)
Public utilities, property, plant and equipment, net	6,169.8	6,006.2
Other property	8.4	8.3
Total property, plant and equipment, net	6,178.2	6,014.5
Other assets
Unamortized debt expense	17.1	14.8
Regulatory assets	283.9	293.1
Derivative assets	0.5	0.3
Deferred charges and other assets	305.3	312.8
Other	3.8	4.6
Total assets	7,051.9	6,875.8
Current liabilities
Long-term debt due within one year	83.3	83.3
Notes payable	0	84.0
Accounts payable	198.2	226.0
Customer deposits	167.5	164.5
Regulatory liabilities	65.7	85.8
Derivative liabilities	0.2	0
Interest accrued	18.6	16.4
Taxes accrued	57.8	12.2
Other	12.1	12.0
Total current liabilities	603.4	684.2
Other liabilities
Deferred income taxes	1,145.1	1,114.3
Investment tax credits	9.2	9.4
Regulatory liabilities	621.4	631.4
Derivative liabilities	0.1	0.2
Other	293.4	308.1
Long-term debt, less amount due within one year	2,013.9	1,797.5
Total other liabilities	2,069.2	2,063.4
Commitments and contingencies (see Note 10)
Capital
Common equity	2,047.4	2,030.4
Retained earnings	325.6	308.1
Accumulated other comprehensive loss	(7.6)	(7.8)
Total capital	2,365.4	2,330.7
Total capitalization	4,379.3	4,128.2
Total liabilities and capital	7,051.9	6,875.8
Tampa Electric Company [Member] | Fuel [Member]
Inventories, at average cost
Utility inventories	98.7	93.7
Tampa Electric Company [Member] | Materials and supplies [Member]
Inventories, at average cost
Utility inventories	74.4	76.8
Tampa Electric Company [Member] | Electric [Member]
Property, plant and equipment
Public utilities, property, plant and equipment	6,941.7	6,934.0
Tampa Electric Company [Member] | Gas [Member]
Property, plant and equipment
Public utilities, property, plant and equipment	$ 1,265.6	$ 1,249.5