Shareholders' Equity - Accumulated Other Comprehensive Income (Loss) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2020 USD ($)
Summary of the components of accumulated other comprehensive income, net of tax
Balance at beginning of period	$ 917.1
Balance at end of period	962.7
Accumulated Other Comprehensive Income (Loss)
Summary of the components of accumulated other comprehensive income, net of tax
Balance at beginning of period	(25.5)
Other comprehensive income (loss) before reclassifications	17.1
Amounts reclassified from other comprehensive income (loss), net of tax	3.2
Net current period other comprehensive income (loss)	20.3
Balance at end of period	(5.2)
Foreign Currency Translation
Summary of the components of accumulated other comprehensive income, net of tax
Balance at beginning of period	27.4
Other comprehensive income (loss) before reclassifications	5.4
Net current period other comprehensive income (loss)	5.4
Balance at end of period	32.8
Pension Liability Adjustment
Summary of the components of accumulated other comprehensive income, net of tax
Balance at beginning of period	(52.9)
Other comprehensive income (loss) before reclassifications	11.7
Amounts reclassified from other comprehensive income (loss), net of tax	3.2
Net current period other comprehensive income (loss)	14.9
Balance at end of period	$ (38.0)