Accumulated Other Comprehensive Loss - Changes in AOCI (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning equity	$ 2,240.7
Other comprehensive income (loss) before reclassifications	2.8
Amounts reclassified from accumulated other comprehensive loss	2.6
Other comprehensive income (loss)	5.4	$ (4.6)
Ending equity	2,224.4
Cash flow hedge (loss) gain
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning equity	0.4
Other comprehensive income (loss) before reclassifications	(0.6)
Amounts reclassified from accumulated other comprehensive loss	0.0
Other comprehensive income (loss)	(0.6)
Ending equity	(0.2)
Unrealized gain (loss) on available-for- sale securities
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning equity	0.6
Other comprehensive income (loss) before reclassifications	(1.2)
Amounts reclassified from accumulated other comprehensive loss	0.0
Other comprehensive income (loss)	(1.2)
Ending equity	(0.6)
Pension and post retirement benefit plan adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning equity	(202.8)
Other comprehensive income (loss) before reclassifications	0.0
Amounts reclassified from accumulated other comprehensive loss	2.1
Other comprehensive income (loss)	2.1
Ending equity	(200.7)
Cumulative translation adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning equity	(129.0)
Other comprehensive income (loss) before reclassifications	4.6
Amounts reclassified from accumulated other comprehensive loss	0.5
Other comprehensive income (loss)	5.1
Ending equity	(123.9)
Total
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning equity	(330.8)	(329.2)
Other comprehensive income (loss)	5.4	(4.6)
Ending equity	$ (325.4)	$ (333.8)