Comprehensive Income (Changes in AOCL) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Changes in AOCI by component (net of tax) [Roll Forward]
Balance as of beginning of period	$ (103.8)
Other comprehensive loss before reclassifications	(31.4)
Amounts reclassified from AOCL	2.1
Net other comprehensive (loss) income	(29.3)
Balance as of end of period	(133.1)
Gains (Losses) on Cash Flow Hedges [Member]
Changes in AOCI by component (net of tax) [Roll Forward]
Balance as of beginning of period	0.0
Other comprehensive loss before reclassifications	(10.5)
Amounts reclassified from AOCL	0.9
Net other comprehensive (loss) income	(9.6)
Balance as of end of period	(9.6)
Defined Benefit Pension Plan Items [Member]
Changes in AOCI by component (net of tax) [Roll Forward]
Balance as of beginning of period	(81.5)
Other comprehensive loss before reclassifications	(0.6)
Amounts reclassified from AOCL	1.2
Net other comprehensive (loss) income	0.6
Balance as of end of period	(80.9)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Changes in AOCI by component (net of tax) [Roll Forward]
Balance as of beginning of period	(22.3)
Other comprehensive loss before reclassifications	(20.3)
Amounts reclassified from AOCL	0.0	$ 2.1
Net other comprehensive (loss) income	(20.3)
Balance as of end of period	$ (42.6)