Employee Postretirement Benefits (Tables)

6 Months Ended

Jun. 30, 2015

Compensation And Retirement Disclosure [Abstract]

Schedule of Net Periodic Benefit Cost

Included in the table below is the periodic expense for pension and other postretirement benefits offered by the company.

Pension Expense
(millions)	Pension Benefits						Other Postretirement Benefits
Three months ended June 30,	2015			2014			2015			2014
Components of net periodic benefit expense
Service cost	$	6.4		$	4.2		$	0.5		$	0.6
Interest cost		8.7			8.2			2.1			2.6
Expected return on assets		(12.5	)		(10.4	)		(0.2	)		0.0
Amortization of:
Prior service (benefit) cost		0.0			(0.1	)		(0.6	)		(0.1	)
Actuarial loss		4.8			3.5			0.0			0.1
Regulatory asset		0.0			0.0			0.2			0.0
Net pension expense recognized in the    TECO Energy Consolidated Condensed Statements of Income	$	7.4		$	5.4		$	2.0		$	3.2
Six months ended June 30,
Components of net periodic benefit expense
Service cost	$	10.9		$	8.3		$	1.1		$	1.2
Interest cost		16.1			16.4			4.1			5.2
Expected return on assets		(23.3	)		(20.7	)		(0.5	)		0.0
Amortization of:
Prior service (benefit) cost		(0.1	)		(0.2	)		(1.2	)		(0.1	)
Actuarial loss		8.2			6.7			0.0			0.1
Regulatory asset		0.0			0.0			0.5			0.0
Net pension expense recognized in the    TECO Energy Consolidated Condensed Statements of Income	$	11.8		$	10.5		$	4.0		$	6.4