Restructuring and Repositioning Expenses, Asset Impairments - Estimated and Actual Costs (Details) $ in Millions	Jun. 30, 2020 USD ($)
Restructuring Cost and Reserve [Line Items]
Decrease in expected costs	$ 2.0
2019 Plan
Restructuring Cost and Reserve [Line Items]
Cost to date	12.5
Capital expenditures to date	1.7
2019 Plan | Minimum
Restructuring Cost and Reserve [Line Items]
Estimated costs	15.0
Estimated capital expenditures	2.0
2019 Plan | Maximum
Restructuring Cost and Reserve [Line Items]
Estimated costs	18.0
Estimated capital expenditures	3.0
2019 Phase 2 Plan
Restructuring Cost and Reserve [Line Items]
Estimated capital expenditures	2.0
Cost to date	9.4
Capital expenditures to date	0.4
2019 Phase 2 Plan | Minimum
Restructuring Cost and Reserve [Line Items]
Estimated costs	23.0
2019 Phase 2 Plan | Maximum
Restructuring Cost and Reserve [Line Items]
Estimated costs	28.0
Total Restructuring | 2019 Plan
Restructuring Cost and Reserve [Line Items]
Cost to date	2.1
Total Restructuring | 2019 Plan | Specialty Construction Chemicals
Restructuring Cost and Reserve [Line Items]
Cost to date	1.7
Total Restructuring | 2019 Plan | Specialty Building Materials
Restructuring Cost and Reserve [Line Items]
Cost to date	0.4
Total Restructuring | 2019 Plan | Minimum
Restructuring Cost and Reserve [Line Items]
Estimated costs	4.0
Total Restructuring | 2019 Plan | Maximum
Restructuring Cost and Reserve [Line Items]
Estimated costs	6.0
Total Restructuring | 2019 Phase 2 Plan
Restructuring Cost and Reserve [Line Items]
Cost to date	5.1
Total Restructuring | 2019 Phase 2 Plan | Specialty Construction Chemicals
Restructuring Cost and Reserve [Line Items]
Cost to date	3.0
Total Restructuring | 2019 Phase 2 Plan | Specialty Building Materials
Restructuring Cost and Reserve [Line Items]
Cost to date	2.1
Total Restructuring | 2019 Phase 2 Plan | Minimum
Restructuring Cost and Reserve [Line Items]
Estimated costs	16.0
Total Restructuring | 2019 Phase 2 Plan | Maximum
Restructuring Cost and Reserve [Line Items]
Estimated costs	20.0
Severance/employee costs | 2019 Plan
Restructuring Cost and Reserve [Line Items]
Cost to date	0.9
Severance/employee costs | 2019 Plan | Minimum
Restructuring Cost and Reserve [Line Items]
Estimated costs	2.0
Severance/employee costs | 2019 Plan | Maximum
Restructuring Cost and Reserve [Line Items]
Estimated costs	3.0
Severance/employee costs | 2019 Phase 2 Plan
Restructuring Cost and Reserve [Line Items]
Cost to date	4.8
Severance/employee costs | 2019 Phase 2 Plan | Minimum
Restructuring Cost and Reserve [Line Items]
Estimated costs	13.0
Severance/employee costs | 2019 Phase 2 Plan | Maximum
Restructuring Cost and Reserve [Line Items]
Estimated costs	16.0
Asset Impairments | 2019 Plan
Restructuring Cost and Reserve [Line Items]
Estimated costs	1.0
Cost to date	0.9
Asset Impairments | 2019 Phase 2 Plan
Restructuring Cost and Reserve [Line Items]
Estimated costs	0.0
Cost to date	0.3
Other Associated Costs | 2019 Plan
Restructuring Cost and Reserve [Line Items]
Cost to date	0.3
Other Associated Costs | 2019 Plan | Minimum
Restructuring Cost and Reserve [Line Items]
Estimated costs	1.0
Other Associated Costs | 2019 Plan | Maximum
Restructuring Cost and Reserve [Line Items]
Estimated costs	2.0
Other Associated Costs | 2019 Phase 2 Plan
Restructuring Cost and Reserve [Line Items]
Cost to date	0.0
Other Associated Costs | 2019 Phase 2 Plan | Minimum
Restructuring Cost and Reserve [Line Items]
Estimated costs	3.0
Other Associated Costs | 2019 Phase 2 Plan | Maximum
Restructuring Cost and Reserve [Line Items]
Estimated costs	4.0
Repositioning | 2019 Plan
Restructuring Cost and Reserve [Line Items]
Cost to date	10.4
Capital expenditures to date	10.1
Repositioning | 2019 Plan | Minimum
Restructuring Cost and Reserve [Line Items]
Estimated costs	11.0
Repositioning | 2019 Plan | Maximum
Restructuring Cost and Reserve [Line Items]
Estimated costs	12.0
Repositioning | 2019 Phase 2 Plan
Restructuring Cost and Reserve [Line Items]
Cost to date	4.3
Capital expenditures to date	3.8
Repositioning | 2019 Phase 2 Plan | Minimum
Restructuring Cost and Reserve [Line Items]
Estimated costs	7.0
Repositioning | 2019 Phase 2 Plan | Maximum
Restructuring Cost and Reserve [Line Items]
Estimated costs	$ 8.0