Consolidated Condensed Statements of Income and Comprehensive Income (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Franchise fees and gross receipts taxes	$ 29.7	$ 31.0	$ 81.8	$ 85.4
Tampa Electric Company [Member]
Franchise fees and gross receipts taxes	29.7	31.0	81.8	85.4
Tampa Electric Company [Member] | Electric [Member]
Franchise fees and gross receipts taxes	25.6	26.7	66.1	70.0
Tampa Electric Company [Member] | Gas [Member]
Franchise fees and gross receipts taxes	$ 4.1	$ 4.3	$ 15.7	$ 15.4