Pension and Other Postretirement Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Pension [Member]
Components of Net Periodic Benefit Expense (Income) [Abstract]
Service Cost	$ 2.0	$ 2.6	$ 6.1	$ 7.6
Interest Cost	8.2	7.5	24.4	22.4
Expected Return on Plan Assets	(10.7)	(10.2)	(32.0)	(30.5)
Amortization of Prior Service Costs (Credits)	0.0	0.0	0.0	0.1
Amortization of Net Loss	2.4	4.4	7.3	13.4
Net Periodic Benefit Expense (Income)	1.9	4.3	5.8	13.0
Contributions			6.3	0.0
Expected Future Contributions in 2016			0.0
Other Postretirement [Member]
Components of Net Periodic Benefit Expense (Income) [Abstract]
Service Cost	1.0	1.0	3.0	3.2
Interest Cost	1.9	1.8	5.6	5.4
Expected Return on Plan Assets	(2.8)	(2.7)	(8.4)	(8.2)
Amortization of Prior Service Costs (Credits)	(0.7)	(0.7)	(2.2)	(2.2)
Amortization of Net Loss	0.0	0.1	0.1	0.3
Net Periodic Benefit Expense (Income)	$ (0.6)	$ (0.5)	(1.9)	(1.5)
Contributions			0.0	$ 0.0
Expected Future Contributions in 2016			$ 0.0