Accumulated Other Comprehensive Loss, Net of Tax (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	$ (1.3)	$ (1.4)
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax	(223.7)	(213.9)	$ (228.8)	$ (219.4)
Foreign currency translation adjustment:
Balance at beginning of period	(697.7)	(716.4)
Other comprehensive (loss) income before reclassifications	(56.2)	(37.2)
Amount reclassified from accumulated other comprehensive loss, net of tax	9.3	5.2
Balance at end of period	(744.6)	(748.4)
Derivative Instrument:
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	2.7	0.0
Defined Benefit Pension and Other Postretirement Plans
Balance at beginning of period	(3.5)	(5.3)
Other comprehensive (loss) income before reclassifications	0.8	1.6
Amount reclassified from accumulated other comprehensive loss, net of tax	4.3	3.9
Balance at end of period	0.5	(3.9)
Total:
Balance at beginning of period	(930.0)	(941.1)
Other comprehensive (loss) income before reclassifications	(52.7)	(35.6)
Amount reclassified from accumulated other comprehensive loss, net of tax	14.9	10.5
Balance at end of period	$ (967.8)	$ (966.2)