Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2015

Schedule of Recurring Fair Value Measurements

Recurring Fair Value Measures
	As of Mar. 31, 2015
(millions)	Level 1		Level 2		Level 3		Total
Assets
Interest rate swaps	$	0.0	$	0.3	$	0.0	$	0.3
Liabilities
Natural gas swaps	$	0.0	$	40.8	$	0.0	$	40.8
	As of Dec. 31, 2014
(millions)	Level 1		Level 2		Level 3		Total
Liabilities
Natural gas swaps	$	0.0	$	42.7	$	0.0	$	42.7

Tampa Electric Company [Member]

Schedule of Recurring Fair Value Measurements

Recurring Derivative Fair Value Measures
	As of Mar. 31, 2015
(millions)	Level 1		Level 2		Level 3		Total
Assets
Interest rate swaps	$	0.0	$	0.3	$	0.0	$	0.3
Liabilities
Natural gas swaps	$	0.0	$	40.8	$	0.0	$	40.8
	As of Dec. 31, 2014
(millions)	Level 1		Level 2		Level 3		Total
Liabilities
Natural gas swaps	$	0.0	$	42.7	$	0.0	$	42.7