Accumulated Other Comprehensive Loss - Changes in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 1,749.0	$ 1,935.7
Other comprehensive income (loss) before reclassifications	(0.5)
Amounts reclassified from accumulated other comprehensive loss	1.2	1.2
Current period other comprehensive income (loss)	0.7
Ending balance	1,575.7	1,871.2
Cash flow hedge (loss) gain
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	1.4
Other comprehensive income (loss) before reclassifications	(1.5)
Amounts reclassified from accumulated other comprehensive loss	(0.8)
Current period other comprehensive income (loss)	(2.3)
Ending balance	(0.9)
Unrealized gain (loss) on available-for- sale securities
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0.0
Other comprehensive income (loss) before reclassifications	0.3
Amounts reclassified from accumulated other comprehensive loss	0.0
Current period other comprehensive income (loss)	0.3
Ending balance	0.3
Pension and post retirement benefit plan adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(140.2)
Other comprehensive income (loss) before reclassifications	0.0
Amounts reclassified from accumulated other comprehensive loss	2.0	$ 1.7
Current period other comprehensive income (loss)	2.0
Ending balance	(138.2)
Cumulative translation adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(85.4)
Other comprehensive income (loss) before reclassifications	0.7
Amounts reclassified from accumulated other comprehensive loss	0.0
Current period other comprehensive income (loss)	0.7
Ending balance	(84.7)
AOCI Including Portion Attributable to Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(224.2)
Ending balance	$ (223.5)