Consolidated Condensed Balance Sheets (Unaudited) (Parenthetical) (USD $) In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Allowance for uncollectibles	$ 2.5	$ 4.7
Common equity, shares authorized	400.0	400.0
Common equity, par value	$ 1	$ 1
Common equity, shares outstanding	234.6	217.3
Tampa Electric Company [Member]
Allowance for uncollectibles	$ 2.3	$ 2.0