Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement Of Income And Comprehensive Income [Abstract]
Net income attributable to TECO Energy	$ 197.7	$ 212.7	$ 272.6
Other comprehensive income (loss), net of tax
Net unrealized gains (losses) on cash flow hedges	1.4	(4.2)	(0.8)
Amortization of unrecognized benefit costs and other	14.8	(4.8)	(4.6)
Recognized benefit costs due to settlement	1.6	0	0.6
Other comprehensive income (loss), net of tax	17.8	(9.0)	(4.8)
Comprehensive income attributable to TECO Energy	$ 215.5	$ 203.7	$ 267.8