Restructuring Plans (Details) $ in Millions			3 Months Ended		6 Months Ended		12 Months Ended	22 Months Ended	44 Months Ended
	Feb. 21, 2017 USD ($)	Feb. 05, 2015	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Jun. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)
Corporate Relocation Plan
Restructuring Cost and Reserve [Line Items]
Restructuring, number of positions affected		350
Restructuring charges					$ 3.4
Restructuring charges incurred to date			$ 35.2		35.2			$ 35.2
DSD Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring charges incurred to date			4.4		4.4			4.4
Employee-related | Corporate Relocation Plan
Restructuring Cost and Reserve [Line Items]
Payments									$ 17.4
Employee-related | DSD Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring charges			0.2	$ 0.0	1.2	$ 0.0
Payments								2.5
Facility Closing | Corporate Relocation Plan
Restructuring Cost and Reserve [Line Items]
Accelerated depreciation									2.3
Payments									7.0
Other Restructuring | Corporate Relocation Plan
Restructuring Cost and Reserve [Line Items]
Payments									7.4
Sale Leaseback Transaction, Rent Expense							$ 1.4
Other Restructuring | DSD Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring charges			0.0	$ 0.1	0.2	$ 0.2
Payments								1.9
Pension withdrawal liability | Corporate Relocation Plan
Restructuring Cost and Reserve [Line Items]
Payments									$ 3.4
Pension withdrawal liability | DSD Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Payments					4.2
Expected cost remaining			0.3		0.3			0.3
Maximum | DSD Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Expected restructuring and related costs	$ 4.9
Maximum | Employee-related | DSD Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Expected restructuring and related costs	2.7
Maximum | Other Restructuring | DSD Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Expected restructuring and related costs	$ 2.2
WCTPP [Member]
Restructuring Cost and Reserve [Line Items]
Withdrawal obligation			2.6		2.6			2.6
WCTPP [Member] | Employee-related | Corporate Relocation Plan
Restructuring Cost and Reserve [Line Items]
Multiemployer Plans, Withdrawal Obligation, Amount Paid			0.8		0.8			0.8
Withdrawal obligation			$ 2.6		$ 2.6			$ 2.6