Interest and Other Nonoperating Income (Expense) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Investment [Line Items]
Interest income		$ 5.6	$ 6.9	$ 4.1
Gain (loss) on equity securities		(2.9)	3.2	1.5
Foreign currency transaction losses(a)		0.0	(15.5)	(7.6)
Derivative instruments		0.0	0.0	1.1
Retirement benefit cost other than service cost		(52.7)	(39.7)	(47.8)
Prepayment penalties		0.0	0.0	(8.3)
Interest on Colombia tax claim(h)		(1.1)
Interest on Brazil tax claim(c)		0.0	0.0	(1.6)
Non-income taxes on intercompany billings(d)		(4.2)	(2.6)	(1.3)
Venezuela operations(e)		(0.9)	(0.6)
Gain on lease termination	$ 5.2	5.2
Gain on a disposition of a subsidiary(g)		0.0	11.2	0.0
Other		(1.7)	(1.7)	(0.3)
Total		(52.7)	$ (38.8)	(60.2)
Brazil
Investment [Line Items]
Tax claim				$ 1.0
COLOMBIA
Investment [Line Items]
Tax claim		$ 1.0