Shareholders' Equity (Schedule of Accumulated Other Comprehensive (Loss) Activity) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	$ 402.9	$ 243.1	$ 364.9	$ 226.0
Impact of ASU 2017-12 adoption	857.1		857.1		$ 1,008.2
Other comprehensive (loss) income before reclassifications, net of tax (expense) of $ -, ($0.9), ($0.2) and ($1.1)	(3.3)	(5.6)	(9.1)	(12.2)
Amounts reclassified from accumulated other comprehensive (loss)	(2.2)	87.0	275.4	92.1
Net current period other comprehensive (loss) income	(5.5)	81.4	266.3	79.9
Balance	442.6	367.3	442.6	367.3
ASU 2017-12 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Impact of ASU 2017-12 adoption		0.1		0.1
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	7.4	(68.7)	9.4	(74.7)
Other comprehensive (loss) income before reclassifications, net of tax (expense) of $ -, ($0.9), ($0.2) and ($1.1)	(6.2)	(2.6)	(8.2)	3.4
Amounts reclassified from accumulated other comprehensive (loss)		81.2		81.2
Net current period other comprehensive (loss) income	(6.2)	78.6	(8.2)	84.6
Balance	1.2	9.9	1.2	9.9
Derivative Gain (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	(22.3)	(7.8)	(8.5)	5.3
Other comprehensive (loss) income before reclassifications, net of tax (expense) of $ -, ($0.9), ($0.2) and ($1.1)	3.0	(3.1)	(9.4)	(17.1)
Amounts reclassified from accumulated other comprehensive (loss)	(1.5)	0.4	(2.9)	1.2
Net current period other comprehensive (loss) income	1.5	(2.7)	(12.3)	(15.9)
Balance	(20.8)	(10.5)	(20.8)	(10.5)
Derivative Gain (Loss) [Member] | ASU 2017-12 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Impact of ASU 2017-12 adoption		0.1		0.1
Pension And Postretirement Adjustments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	(89.4)	(384.5)	(377.0)	(390.2)
Other comprehensive (loss) income before reclassifications, net of tax (expense) of $ -, ($0.9), ($0.2) and ($1.1)	(0.1)	0.1	8.5	1.5
Amounts reclassified from accumulated other comprehensive (loss)	(0.7)	5.4	278.3	9.7
Net current period other comprehensive (loss) income	(0.8)	5.5	286.8	11.2
Balance	(90.2)	(379.0)	(90.2)	(379.0)
Accumulated Other Comprehensive (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	(104.3)	(461.0)	(376.1)	(459.6)
Balance	$ (109.8)	$ (379.6)	$ (109.8)	(379.6)
Accumulated Other Comprehensive (Loss) [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance				$ 0.1