Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance		$ (1,176.3)	$ (1,172.8)	$ (1,223.6)	$ (1,201.7)
OCI before reclassifications		1.0	21.9	6.1	6.2
Amounts reclassified from AOCI		14.2	22.3	56.4	66.9
Net current-period OCI		15.2	44.2	62.5	73.1
Ending balance		(1,161.1)	(1,128.6)	(1,161.1)	(1,128.6)
Increase (Decrease) in Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance		23.7	8.5	21.2	9.8
OCI before reclassifications		(0.8)	6.0	1.7	4.7
Amounts reclassified from AOCI		0.0	0.0	0.0	0.0
Net current-period OCI		(0.8)	6.0	1.7	4.7
Ending balance		22.9	14.5	22.9	14.5
Post- retirement benefit plans [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance		(1,086.9)	(1,051.8)	(1,119.9)	(1,083.1)
OCI before reclassifications		0.0	0.0	0.0	0.0
Amounts reclassified from AOCI	[1]	4.0	15.6	37.0	46.9
Net current-period OCI		4.0	15.6	37.0	46.9
Ending balance		(1,082.9)	(1,036.2)	(1,082.9)	(1,036.2)
Increase (Decrease) in Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance		0.0	0.0	0.0	0.0
OCI before reclassifications		0.0	0.0	0.0	0.0
Amounts reclassified from AOCI		0.0	0.0	0.0	0.0
Net current-period OCI		0.0	0.0	0.0	0.0
Ending balance		0.0	0.0	0.0	0.0
Currency translation adjustment [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance		(55.8)	(84.5)	(55.5)	(76.6)
OCI before reclassifications		(4.2)	17.2	(4.5)	9.3
Amounts reclassified from AOCI	[2]	0.0	0.0	0.0	0.0
Net current-period OCI		(4.2)	17.2	(4.5)	9.3
Ending balance		(60.0)	(67.3)	(60.0)	(67.3)
Increase (Decrease) in Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance		23.7	8.5	21.2	9.8
OCI before reclassifications		(0.8)	6.0	1.7	4.7
Amounts reclassified from AOCI	[2]	0.0	0.0	0.0	0.0
Net current-period OCI		(0.8)	6.0	1.7	4.7
Ending balance		22.9	14.5	22.9	14.5
Derivatives [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance		5.1	(3.7)	2.1	(0.5)
OCI before reclassifications		5.2	4.7	10.6	(3.1)
Amounts reclassified from AOCI	[3]	(2.3)	0.3	(4.7)	4.9
Net current-period OCI		2.9	5.0	5.9	1.8
Ending balance		8.0	1.3	8.0	1.3
Increase (Decrease) in Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance		0.0	0.0	0.0	0.0
OCI before reclassifications		0.0	0.0	0.0	0.0
Amounts reclassified from AOCI		0.0	0.0	0.0	0.0
Net current-period OCI		0.0	0.0	0.0	0.0
Ending balance		0.0	0.0	0.0	0.0
Accumulated Deferred Tax Asset Valuation Allowance [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance		(38.7)	(32.8)	(50.3)	(41.5)
OCI before reclassifications		0.0	0.0	0.0	0.0
Amounts reclassified from AOCI	[4]	12.5	6.4	24.1	15.1
Net current-period OCI		12.5	6.4	24.1	15.1
Ending balance		(26.2)	(26.4)	(26.2)	(26.4)
Increase (Decrease) in Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance		0.0	0.0	0.0	0.0
OCI before reclassifications		0.0	0.0	0.0	0.0
Amounts reclassified from AOCI		0.0	0.0	0.0	0.0
Net current-period OCI		0.0	0.0	0.0	0.0
Ending balance		$ 0.0	$ 0.0	$ 0.0	$ 0.0

[1] Amounts were included in net periodic benefit cost for pension and other postretirement benefit plans (see Note 12).

[2] No amounts were reclassified to earnings.

[3] Amounts related to derivatives are included in cost of goods sold or interest expense in the period or periods the hedged item affects earnings (see Note 9).

[4] Represents the net change in deferred tax asset valuation allowances on changes in AOCI balances between the balance sheet dates.