Accumulated Other Comprehensive Loss Changes in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning of period	$ 1,749.0
Other comprehensive (loss) income	(78.3)	$ (59.9)	$ (93.3)
End of period	1,603.2	1,749.0
Cash Flow Hedge (Loss) Gain
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning of period	1.4	0.0	(0.2)
Other comprehensive income (loss) before Reclassifications	(1.4)	1.7	0.9
Amounts reclassified from accumulated other comprehensive loss	0.0	(0.3)	(0.7)
Other comprehensive (loss) income	(1.4)	1.4	0.2
End of period	0.0	1.4	0.0
Unrealized Gain (Loss) on Available-for-Sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning of period	0.0	0.3	0.4
Other comprehensive income (loss) before Reclassifications	(1.2)	(0.3)	(0.1)
Amounts reclassified from accumulated other comprehensive loss	0.0	0.0	0.0
Other comprehensive (loss) income	(1.2)	(0.3)	(0.1)
End of period	(1.2)	0.0	0.3
Pension and Post Retirement Benefit Plan Adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning of period	(140.2)	(124.7)	(67.0)
Other comprehensive income (loss) before Reclassifications	(48.5)	(22.5)	(59.8)
Amounts reclassified from accumulated other comprehensive loss	8.2	7.0	2.1
Other comprehensive (loss) income	(40.3)	(15.5)	(57.7)
End of period	(180.5)	(140.2)	(124.7)
Cumulative Translation Adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning of period	(85.4)	(39.9)	(4.2)
Other comprehensive income (loss) before Reclassifications	(35.4)	(45.5)	(35.7)
Amounts reclassified from accumulated other comprehensive loss	0.0	0.0	0.0
Other comprehensive (loss) income	(35.4)	(45.5)	(35.7)
End of period	(120.8)	(85.4)	(39.9)
AOCI Attributable to Parent
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning of period	(224.2)	(164.3)	(71.0)
Other comprehensive income (loss) before Reclassifications	(86.5)	(66.6)	(94.7)
Amounts reclassified from accumulated other comprehensive loss	8.2	6.7	1.4
Other comprehensive (loss) income	(78.3)	(59.9)	(93.3)
End of period	$ (302.5)	$ (224.2)	$ (164.3)