Restructuring and Repositioning Expenses - Narrative (Details) $ in Millions			3 Months Ended				9 Months Ended		14 Months Ended	27 Months Ended
	Jul. 31, 2019 USD ($)	Aug. 01, 2018 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) segment	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2019 USD ($)	Feb. 22, 2019 USD ($)	Dec. 31, 2018 USD ($)	Jun. 28, 2017 USD ($) facility
Restructuring Cost and Reserve [Line Items]
Number of operating segments | segment							2
Restructuring liability			$ 4.8				$ 4.8		$ 4.8	$ 4.8		$ 10.2
Other associated costs
Restructuring Cost and Reserve [Line Items]
Restructuring expenses			0.1				0.5
2019 Plan | Severance and other employee costs
Restructuring Cost and Reserve [Line Items]
Restructuring expenses			0.7	$ 0.0	$ 0.0
Cash payments			0.3	0.0	0.0
Restructuring liability			0.4	0.0	0.0		0.4		0.4	0.4		0.0
2019 Plan | Minimum
Restructuring Cost and Reserve [Line Items]
Estimated expenses											$ 15.0
2019 Plan | Maximum
Restructuring Cost and Reserve [Line Items]
Estimated expenses											20.0
2019 Plan, restructuring activities
Restructuring Cost and Reserve [Line Items]
Costs incurred to date			0.7				0.7		0.7	0.7
2019 Plan, restructuring activities | SCC
Restructuring Cost and Reserve [Line Items]
Costs incurred to date			0.4				0.4		0.4	0.4
2019 Plan, restructuring activities | SBM
Restructuring Cost and Reserve [Line Items]
Costs incurred to date			0.3				0.3		0.3	0.3
2019 Plan, restructuring activities | Asset impairments
Restructuring Cost and Reserve [Line Items]
Estimated expenses											1.0
2019 Plan, restructuring activities | Minimum
Restructuring Cost and Reserve [Line Items]
Estimated expenses											4.0
2019 Plan, restructuring activities | Minimum | Severance and other employee costs
Restructuring Cost and Reserve [Line Items]
Estimated expenses											2.0
2019 Plan, restructuring activities | Minimum | Other associated costs
Restructuring Cost and Reserve [Line Items]
Estimated expenses											1.0
2019 Plan, restructuring activities | Maximum
Restructuring Cost and Reserve [Line Items]
Estimated expenses											7.0
2019 Plan, restructuring activities | Maximum | Severance and other employee costs
Restructuring Cost and Reserve [Line Items]
Estimated expenses											3.0
2019 Plan, restructuring activities | Maximum | Other associated costs
Restructuring Cost and Reserve [Line Items]
Estimated expenses											3.0
2019 Plan, repositioning activities
Restructuring Cost and Reserve [Line Items]
Restructuring expenses			3.1				6.4
Cash payments			1.4				3.7
2019 Plan, repositioning activities | Capital expenditures
Restructuring Cost and Reserve [Line Items]
Costs incurred to date			0.4				0.4		0.4	0.4
Cash payments			0.1				0.3
2019 Plan, repositioning activities | Minimum
Restructuring Cost and Reserve [Line Items]
Estimated expenses											11.0
2019 Plan, repositioning activities | Minimum | Capital expenditures
Restructuring Cost and Reserve [Line Items]
Estimated expenses											2.0
2019 Plan, repositioning activities | Maximum
Restructuring Cost and Reserve [Line Items]
Estimated expenses											13.0
2019 Plan, repositioning activities | Maximum | Capital expenditures
Restructuring Cost and Reserve [Line Items]
Estimated expenses											$ 3.0
2019 Phase 2 Plan | Severance and other employee costs
Restructuring Cost and Reserve [Line Items]
Restructuring expenses			2.9	0.0	0.0
Cash payments			0.5	0.0	0.0
Restructuring liability			2.4	0.0	0.0		2.4		2.4	2.4		0.0
2019 Phase 2 Plan | Minimum
Restructuring Cost and Reserve [Line Items]
Estimated expenses	$ 30.0
2019 Phase 2 Plan | Maximum
Restructuring Cost and Reserve [Line Items]
Estimated expenses	35.0
2019 Phase 2 Plan, restructuring activities
Restructuring Cost and Reserve [Line Items]
Restructuring expenses			2.9				2.9
2019 Phase 2 Plan, restructuring activities | SCC
Restructuring Cost and Reserve [Line Items]
Restructuring expenses			1.7				1.7
2019 Phase 2 Plan, restructuring activities | SBM
Restructuring Cost and Reserve [Line Items]
Restructuring expenses			1.2				1.2
2019 Phase 2 Plan, restructuring activities | Minimum
Restructuring Cost and Reserve [Line Items]
Estimated expenses	$ 23.0
Number of positions eliminated as a percent of total employees	8.00%
2019 Phase 2 Plan, restructuring activities | Minimum | Severance and other employee costs
Restructuring Cost and Reserve [Line Items]
Estimated expenses	$ 19.0
2019 Phase 2 Plan, restructuring activities | Minimum | Other associated costs
Restructuring Cost and Reserve [Line Items]
Estimated expenses	4.0
2019 Phase 2 Plan, restructuring activities | Maximum
Restructuring Cost and Reserve [Line Items]
Estimated expenses	$ 27.0
Number of positions eliminated as a percent of total employees	10.00%
2019 Phase 2 Plan, restructuring activities | Maximum | Severance and other employee costs
Restructuring Cost and Reserve [Line Items]
Estimated expenses	$ 22.0
2019 Phase 2 Plan, restructuring activities | Maximum | Other associated costs
Restructuring Cost and Reserve [Line Items]
Estimated expenses	5.0
2019 Phase 2 Plan, repositioning activities
Restructuring Cost and Reserve [Line Items]
Restructuring expenses			0.4				0.4
2019 Phase 2 Plan, repositioning activities | Capital expenditures
Restructuring Cost and Reserve [Line Items]
Estimated expenses	2.0
2019 Phase 2 Plan, repositioning activities | Minimum
Restructuring Cost and Reserve [Line Items]
Estimated expenses	7.0
2019 Phase 2 Plan, repositioning activities | Maximum
Restructuring Cost and Reserve [Line Items]
Estimated expenses	$ 8.0
2018 Plan | Severance and other employee costs
Restructuring Cost and Reserve [Line Items]
Restructuring expenses			(0.1)	0.0	0.4
Cash payments			1.6	2.3	2.2
Restructuring liability			1.7	3.5	5.8		1.7		1.7	1.7		7.7
2018 Plan | Other associated costs
Restructuring Cost and Reserve [Line Items]
Restructuring expenses			0.1	0.2	0.1
Cash payments			0.1	0.2	0.0
Restructuring liability			0.1	0.1	0.1		0.1		0.1	0.1		0.0
2018 Plan | Minimum
Restructuring Cost and Reserve [Line Items]
Estimated expenses		$ 32.0
2018 Plan | Minimum | Capital expenditures
Restructuring Cost and Reserve [Line Items]
Estimated expenses		1.0
2018 Plan | Maximum
Restructuring Cost and Reserve [Line Items]
Estimated expenses		35.0
2018 Plan | Maximum | Capital expenditures
Restructuring Cost and Reserve [Line Items]
Estimated expenses		2.0
2018 Plan, restructuring activities
Restructuring Cost and Reserve [Line Items]
Costs incurred to date			21.1				21.1		21.1	21.1
2018 Plan, restructuring activities | SCC
Restructuring Cost and Reserve [Line Items]
Costs incurred to date			15.7				15.7		15.7	15.7
2018 Plan, restructuring activities | SBM
Restructuring Cost and Reserve [Line Items]
Costs incurred to date			5.4				5.4		5.4	5.4
2018 Plan, restructuring activities | Severance and other employee costs
Restructuring Cost and Reserve [Line Items]
Costs incurred to date			11.7				11.7		11.7	11.7
2018 Plan, restructuring activities | Other associated costs
Restructuring Cost and Reserve [Line Items]
Costs incurred to date			1.0				1.0		1.0	1.0
2018 Plan, restructuring activities | Asset impairments
Restructuring Cost and Reserve [Line Items]
Costs incurred to date			7.8				7.8		7.8	7.8
2018 Plan, restructuring activities | Facility exit costs
Restructuring Cost and Reserve [Line Items]
Estimated expenses		1.0
Costs incurred to date			0.6				0.6		0.6	0.6
2018 Plan, restructuring activities | Minimum
Restructuring Cost and Reserve [Line Items]
Estimated expenses		$ 21.0
Number of positions eliminated as a percent of total employees		8.00%
2018 Plan, restructuring activities | Minimum | SCC
Restructuring Cost and Reserve [Line Items]
Estimated expenses		$ 16.0
2018 Plan, restructuring activities | Minimum | SBM
Restructuring Cost and Reserve [Line Items]
Estimated expenses		5.0
2018 Plan, restructuring activities | Minimum | Severance and other employee costs
Restructuring Cost and Reserve [Line Items]
Estimated expenses		12.0
2018 Plan, restructuring activities | Minimum | Other associated costs
Restructuring Cost and Reserve [Line Items]
Estimated expenses		1.0
2018 Plan, restructuring activities | Minimum | Asset impairments
Restructuring Cost and Reserve [Line Items]
Estimated expenses		7.0
2018 Plan, restructuring activities | Maximum
Restructuring Cost and Reserve [Line Items]
Estimated expenses		$ 24.0
Number of positions eliminated as a percent of total employees		10.00%
2018 Plan, restructuring activities | Maximum | SCC
Restructuring Cost and Reserve [Line Items]
Estimated expenses		$ 18.0
2018 Plan, restructuring activities | Maximum | SBM
Restructuring Cost and Reserve [Line Items]
Estimated expenses		6.0
2018 Plan, restructuring activities | Maximum | Severance and other employee costs
Restructuring Cost and Reserve [Line Items]
Estimated expenses		13.0
2018 Plan, restructuring activities | Maximum | Other associated costs
Restructuring Cost and Reserve [Line Items]
Estimated expenses		2.0
2018 Plan, restructuring activities | Maximum | Asset impairments
Restructuring Cost and Reserve [Line Items]
Estimated expenses		8.0
2018 Plan, repositioning activities
Restructuring Cost and Reserve [Line Items]
Estimated expenses		$ 11.0
Costs incurred to date			10.6				10.6		10.6	10.6
Restructuring expenses			0.2			$ 2.6	5.3	$ 2.6
Cash payments							8.7		8.9
2018 Plan, repositioning activities | Capital expenditures
Restructuring Cost and Reserve [Line Items]
Costs incurred to date			0.8				0.8		0.8	0.8
Cash payments							0.8
2017 Plan
Restructuring Cost and Reserve [Line Items]
Estimated expenses													$ 29.0
Number of plants to replace sold facilities | facility													2
2017 Plan | Severance and other employee costs
Restructuring Cost and Reserve [Line Items]
Restructuring expenses			0.1	(0.1)	0.0
Cash payments			0.1	0.1	1.5
Restructuring liability			0.2	0.2	0.3		0.2		0.2	0.2		1.8
2017 Plan | Minimum | Capital expenditures
Restructuring Cost and Reserve [Line Items]
Estimated expenses													$ 10.0
2017 Plan | Maximum | Capital expenditures
Restructuring Cost and Reserve [Line Items]
Estimated expenses													15.0
2017 Plan, restructuring activities
Restructuring Cost and Reserve [Line Items]
Estimated expenses													19.0
Costs incurred to date			19.1				19.1		19.1	19.1
2017 Plan, restructuring activities | Discontinued operations
Restructuring Cost and Reserve [Line Items]
Costs incurred to date			8.4				8.4		8.4	8.4
2017 Plan, restructuring activities | SCC
Restructuring Cost and Reserve [Line Items]
Costs incurred to date			4.6				4.6		4.6	4.6
2017 Plan, restructuring activities | SBM
Restructuring Cost and Reserve [Line Items]
Costs incurred to date			3.3				3.3		3.3	3.3
2017 Plan, restructuring activities | Corporate
Restructuring Cost and Reserve [Line Items]
Costs incurred to date			2.8				2.8		2.8	2.8
2017 Plan, restructuring activities | Severance and other employee costs
Restructuring Cost and Reserve [Line Items]
Costs incurred to date			17.4				17.4		17.4	17.4
2017 Plan, restructuring activities | Asset impairments
Restructuring Cost and Reserve [Line Items]
Costs incurred to date			1.5				1.5		1.5	1.5
2017 Plan, restructuring activities | Facility exit costs
Restructuring Cost and Reserve [Line Items]
Costs incurred to date			0.2				0.2		0.2	0.2
2017 Plan, repositioning activities
Restructuring Cost and Reserve [Line Items]
Estimated expenses													$ 10.0
Costs incurred to date			9.5				9.5		9.5	9.5
Restructuring expenses			0.4			$ 1.1	0.7	$ 3.1
Cash payments							3.7			17.8
2017 Plan, repositioning activities | Capital expenditures
Restructuring Cost and Reserve [Line Items]
Costs incurred to date			11.3				11.3		11.3	11.3
Cash payments							2.0
Total
Restructuring Cost and Reserve [Line Items]
Restructuring expenses			3.7	0.4	0.4
Cash payments			2.6	3.1	4.0
Restructuring liability			4.8	$ 3.8	$ 6.4		4.8		$ 4.8	$ 4.8		$ 10.2
Strategic Alternatives Plan
Restructuring Cost and Reserve [Line Items]
Restructuring expenses			0.3				2.8
Cash payments			$ 0.5				$ 0.5