Consolidated Statements of Retained Earnings - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Beginning Balance	$ 479.6
Add: Net income	173.5	$ 130.4	$ 197.7
Deduct: Cash dividends on capital stock—common	211.7	199.2	191.2
Ending Balance	441.4	479.6
Tampa Electric Company [Member]
Beginning Balance	305.8	308.1	304.6
Add: Net income	276.3	260.3	225.6
Retained Earning, Gross	582.1	568.4	530.2
Deduct: Cash dividends on capital stock—common	268.4	262.6	222.1
Ending Balance	$ 313.7	$ 305.8	$ 308.1