Restructuring and Repositioning Expenses, Asset Impairments - Restructuring Liability (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Restructuring Reserve [Roll Forward]
Beginning balance	$ 3.3	$ 2.7		$ 2.7
Expense	0.2	2.1
Payments	(0.7)	(1.3)
Impact of foreign currency and other		(0.2)
Ending balance	2.8	3.3		2.8
2019 Plan | Severance and other employee costs
Restructuring Reserve [Roll Forward]
Beginning balance	0.3	0.2		0.2
Expense	0.0	0.2
Payments	(0.1)	(0.1)
Impact of foreign currency and other		0.0
Ending balance	0.2	0.3		0.2
2019 Plan | Other Costs
Restructuring Reserve [Roll Forward]
Beginning balance	0.2	0.0		0.0
Expense	0.1	0.2
Payments	(0.1)	0.0
Impact of foreign currency and other		0.0
Ending balance	0.2	0.2		0.2
2019 Plan | Asset Impairments | Specialty Construction Chemicals
Restructuring Reserve [Roll Forward]
Expense	0.1			1.1
2019 Plan | Asset Impairments | Specialty Building Materials
Restructuring Reserve [Roll Forward]
Expense	0.1			0.1
2019 Phase 2 Plan | Severance and other employee costs
Restructuring Reserve [Roll Forward]
Beginning balance	2.0	0.9		0.9
Expense	0.0	1.7
Payments	(0.3)	(0.6)
Impact of foreign currency and other		0.0
Ending balance	1.7	2.0		1.7
2018 Plan, Repositioning
Restructuring Reserve [Roll Forward]
Expense	0.1		$ 1.8	0.1	$ 5.1
Payments	0.0		(2.6)	0.0	(7.7)
2018 Plan, Repositioning | Severance and other employee costs
Restructuring Reserve [Roll Forward]
Beginning balance	0.7	1.0		1.0
Expense	0.0	0.0
Payments	(0.1)	(0.2)
Impact of foreign currency and other		(0.1)
Ending balance	0.6	0.7		0.6
2018 Plan, Repositioning | Other Costs
Restructuring Reserve [Roll Forward]
Beginning balance	0.0	0.4		0.4
Expense	0.1	0.0
Payments	(0.1)	(0.3)
Impact of foreign currency and other		(0.1)
Ending balance	0.0	0.0		0.0
2017 Plan, Repositioning
Restructuring Reserve [Roll Forward]
Expense	0.0		0.2	0.1	0.3
Payments	(0.2)		$ (0.3)	(0.2)	$ (1.5)
2017 Plan, Repositioning | Severance and other employee costs
Restructuring Reserve [Roll Forward]
Beginning balance	0.1	0.2		0.2
Expense	0.0	0.0
Payments	0.0	(0.1)
Impact of foreign currency and other		0.0
Ending balance	$ 0.1	$ 0.1		$ 0.1