Comprehensive Income, Accumulated Other Comprehensive Loss, Net of Related Tax (Details) $ in Millions	9 Months Ended
	Sep. 30, 2018 USD ($)
Components of Accumulated Other Comprehensive Loss, Net of Tax [Roll Forward]
Balance at beginning of period	$ 1,251.7	[1]
Other comprehensive loss before reclassifications	(61.0)
Amounts reclassified from AOCI	8.3
Net current period other comprehensive income (loss)	(52.7)
Balance at end of period	1,310.2	[2]
AOCI Attributable to Parent [Member]
Components of Accumulated Other Comprehensive Loss, Net of Tax [Roll Forward]
Balance at beginning of period	(186.1)
Balance at end of period	(238.8)
Foreign Currency Translation Adjustment [Member]
Components of Accumulated Other Comprehensive Loss, Net of Tax [Roll Forward]
Balance at beginning of period	(104.1)
Other comprehensive loss before reclassifications	(61.0)
Amounts reclassified from AOCI	0.0
Net current period other comprehensive income (loss)	(61.0)
Balance at end of period	(165.1)
Unrecognized Pension Costs [Member]
Components of Accumulated Other Comprehensive Loss, Net of Tax [Roll Forward]
Balance at beginning of period	(86.5)
Other comprehensive loss before reclassifications	0.0
Amounts reclassified from AOCI	8.4
Net current period other comprehensive income (loss)	8.4
Balance at end of period	(78.1)
Net Gain (Loss) on Derivatives [Member]
Components of Accumulated Other Comprehensive Loss, Net of Tax [Roll Forward]
Balance at beginning of period	4.5
Other comprehensive loss before reclassifications	0.0
Amounts reclassified from AOCI	(0.1)
Net current period other comprehensive income (loss)	(0.1)
Balance at end of period	$ 4.4

[1] Condensed from audited financial statements

[2] Unaudited