Shareholders' Equity - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Summary of the components of accumulated other comprehensive income, net of tax
Balance at beginning of period	$ 905.1	$ 733.5	$ 693.1
Balance at end of period	917.1	905.1	733.5
Accumulated Other Comprehensive Income (Loss)
Summary of the components of accumulated other comprehensive income, net of tax
Balance at beginning of period	17.0	27.0	(75.9)
Other comprehensive income	(44.6)	(13.4)	98.1
Realized loss on reclassification	2.1	3.4	4.8
Balance at end of period	(25.5)	17.0	27.0
Foreign Currency Translation
Summary of the components of accumulated other comprehensive income, net of tax
Balance at beginning of period	46.9	72.2	(24.1)
Other comprehensive income	(19.5)	(25.3)	96.3
Realized loss on reclassification
Balance at end of period	27.4	46.9	72.2
Pension Liability Adjustment
Summary of the components of accumulated other comprehensive income, net of tax
Balance at beginning of period	(29.9)	(45.2)	(51.8)
Other comprehensive income	(25.1)	11.9	1.8
Realized loss on reclassification	2.1	3.4	4.8
Balance at end of period	$ (52.9)	$ (29.9)	$ (45.2)