Employee Benefit Plans Pre-tax Amounts Recorded in AOCI (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net actuarial gain (loss)	$ (222.9)	$ (215.3)
Net prior service credit	0.6	0.7
Total amounts recorded	(222.3)	(214.6)
Other Postretirement Benefit Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net actuarial gain (loss)	1.1	(35.7)
Net prior service credit	12.7	15.4
Total amounts recorded	$ 13.8	$ (20.3)