Other Expense Restructuring and Related Charges (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2019
Restructuring Cost and Reserve [Line Items]
Payments to acquire property, plant, and equipment			$ 57.1	$ 48.2
Severance charges	$ 1.3	$ 1.3	1.6	3.3
Other charges	0.1	0.6	0.4	1.8
Restructuring and related charges	1.4	2.2	2.0	5.5
Restructuring Reserve [Roll Forward]
Charges	1.4	2.2	2.0	5.5
Non-cash asset-write-downs			(0.4)	(0.4)
Severance and benefits [Member]
Restructuring Reserve [Roll Forward]
Balance, December 31, 2018			2.3
Charges			1.6
Cash payments			(1.6)
Non-cash asset-write-downs			0.0
Balance, June 30, 2019	2.3		2.3
Asset-related charges [Member]
Restructuring Reserve [Roll Forward]
Cash payments			0.0
Other charges [Member]
Restructuring Reserve [Roll Forward]
Cash payments			0.0
2018 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost incurred	10.8		10.8
Severance charges	1.3	1.3	1.6	3.3
Asset impairment charges, equipment		0.3		0.4
Other charges	0.1	0.6	0.4	1.8
Restructuring and related charges	1.4	$ 2.2	2.0	$ 5.5
Restructuring Reserve [Roll Forward]
Balance, December 31, 2018			2.3
Charges			2.0
Cash payments			(1.6)
Non-cash asset-write-downs			(0.4)
Balance, June 30, 2019	2.3		2.3
2018 Restructuring Plan [Member] | Asset-related charges [Member]
Restructuring Reserve [Roll Forward]
Balance, December 31, 2018			0.0
Charges			0.0
Non-cash asset-write-downs			0.0
Balance, June 30, 2019	0.0		0.0
2018 Restructuring Plan [Member] | Other charges [Member]
Restructuring Reserve [Roll Forward]
Balance, December 31, 2018			0.0
Charges			0.4
Non-cash asset-write-downs			(0.4)
Balance, June 30, 2019	0.0		0.0
2018 Restructuring Plan [Member] | Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost					$ 16.0
2016 Restructuring Plan [Member]
Restructuring Reserve [Roll Forward]
Balance, June 30, 2019	$ 0.2		$ 0.2