Subsequent Events - Additional Information (Detail) (USD $)								0 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Tampa Electric Company [Member]	Dec. 17, 2013 Tampa Electric Company [Member]	Dec. 31, 2012 Tampa Electric Company [Member]	Dec. 31, 2013 1-year Accounts Receivable Facility [Member] Tampa Electric Company [Member]	Dec. 31, 2012 1-year Accounts Receivable Facility [Member] Tampa Electric Company [Member]	Feb. 15, 2014 Subsequent Event [Member]	Feb. 15, 2014 Subsequent Event [Member] Tampa Electric Company [Member]	Feb. 15, 2014 Subsequent Event [Member] 1-year Accounts Receivable Facility [Member]	Feb. 15, 2014 Subsequent Event [Member] 1-year Accounts Receivable Facility [Member] Tampa Electric Company [Member]
Subsequent Event [Line Items]
Line of credit facility maximum borrowing capacity	$ 675,000,000	$ 675,000,000	$ 475,000,000	$ 200,000,000	$ 475,000,000	$ 150,000,000	$ 150,000,000		$ 150,000,000	$ 150,000,000	$ 150,000,000
Basis spread on federal funds rate									0.50%	0.50%
Commitment fees, percentage									0.70%	0.70%
Debt instrument maturity date								Feb. 13, 2015	Feb. 13, 2015	Feb. 13, 2015