Other Postretirement Employee Benefit Plans (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Pension and postretirement benefits	$ 1,345.4	$ 1,303.1
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Pension and postretirement benefits	$ 175.0	$ 202.0
Medical trend rate - initial	6.80%	7.10%
Medical trend rate - ultimate	4.50%	4.50%
Unrecognized net prior service credits, before tax	$ 27.0
Unrecognized net prior service credits, net of tax	17.0
Unrecognized actuarial losses, before tax	19.0
Unrecognized actuarial losses, net of tax	12.0
Future amortization of prior service cost (credit)	3.0
Future amortization of prior service cost (credit), net of tax	2.0
Future amortization of gain (loss)	0.2
Future amortization of gain (loss), net of tax	$ 0.1