Pension and Postretirement Health and Life Benefits (Narrative) (Details) (Defined Benefit Pension Plans [Member], USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2014
Defined Benefit Pension Plans [Member]
Expected defined benefit plan contributions for current fiscal year	$ 28.7
Expected defined benefit plan contributions for current fiscal year under ERISA	26.5
Expected defined benefit plan contributions for current fiscal year for non-qualified plans	2.2
USEC contributions	13.1
Defined Benefit Plan, Lump Sum Benefits Paid	$ 16.9