Preferred Stock - Additional Information (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2013
Preferred Stock Par Value [Member]
Authorized Classes Of Cumulative Preferred And Preference Stocks [Line Items]
Preferred stock, par value	$ 1
Preferred stock, shares authorized	10.0
Preferred stock, shares outstanding	0
Preferred Stock Par Value [Member] | Tampa Electric Company [Member]
Authorized Classes Of Cumulative Preferred And Preference Stocks [Line Items]
Preferred stock, par value	$ 100
Preferred stock, shares authorized	1.5
Preferred stock, shares outstanding	0
Preferred Stock No Par Value [Member] | Tampa Electric Company [Member]
Authorized Classes Of Cumulative Preferred And Preference Stocks [Line Items]
Preferred stock, no par value
Preferred stock, shares authorized	2.5
Preferred stock, shares outstanding	0
Preference Stock (Subordinated Preferred Stock) Of Tampa Electric - No Par [Member] | Tampa Electric Company [Member]
Authorized Classes Of Cumulative Preferred And Preference Stocks [Line Items]
Preferred stock, no par value
Preferred stock, shares authorized	2.5
Preferred stock, shares outstanding	0