Significant Accounting Policies (Details) - USD ($) $ in Millions	3 Months Ended									7 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Accounting Policies [Line Items]
Undistributed earnings of foreign subsidiaries		$ 500.0								$ 500.0	$ 500.0
Operating income		(79.6)	$ (58.7)	$ (45.4)	$ (9.3)	$ (59.7)	$ (55.7)	$ (45.4)	$ (6.5)		(193.0)	[1]	$ (167.3)	[1]	$ (163.5)	[1]
Interest Costs Capitalized											0.1		0.1		1.3
Advertising Expense											114.8		110.1		120.9
Research and Development Expense											23.5		21.0		$ 20.0
Goodwill, Impairment Loss				0.0	$ 0.0
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)				$ 0.0
Accounting Standards Update 2016-09
Accounting Policies [Line Items]
Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit, Amount											$ 5.6
Buildings | Minimum
Accounting Policies [Line Items]
Property, plant and equipment, useful life											40 years
Buildings | Maximum
Accounting Policies [Line Items]
Property, plant and equipment, useful life											50 years
Machinery, equipment and furniture | Minimum
Accounting Policies [Line Items]
Property, plant and equipment, useful life											3 years
Machinery, equipment and furniture | Maximum
Accounting Policies [Line Items]
Property, plant and equipment, useful life											10 years
Software and Software Development Costs | Minimum
Accounting Policies [Line Items]
Property, plant and equipment, useful life											5 years
Software and Software Development Costs | Maximum
Accounting Policies [Line Items]
Property, plant and equipment, useful life											10 years
Amortizable Period, Option 1 | Minimum
Accounting Policies [Line Items]
Amortizable life											10 years
Amortizable Period, Option 2
Accounting Policies [Line Items]
Amortizable life											15 years
Amortizable Period, Option 3
Accounting Policies [Line Items]
Amortizable life											23 years
Amortizable Period, Option 4 | Maximum
Accounting Policies [Line Items]
Amortizable life											30 years
Hilroy Trade Name
Accounting Policies [Line Items]
Amortizable life										30 years
Mead Trade Name
Accounting Policies [Line Items]
Long-term growth rate				1.50%
Discount rate				10.50%
Indefinite-Lived Intangible Assets (Excluding Goodwill)		$ 113.3								$ 113.3	$ 113.3
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)				$ 0.0
Maximum Percent Above Carrying Value				30.00%
Hilroy Trade Name
Accounting Policies [Line Items]
Amortizable life										30 years
Long-term growth rate				1.50%
Discount rate				11.00%
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)				$ 0.0
Maximum Percent Above Carrying Value				30.00%
Forecast | Accounting Standards Update 2017-07
Accounting Policies [Line Items]
Cumulative Effect on Retained Earnings, Net of Tax	$ 1.6
Pro Forma | Accounting Standards Update 2017-07
Accounting Policies [Line Items]
Operating income											$ 8.4		$ 8.2

[1] Operating income as presented in the segment table above is defined as i) net sales; ii) less cost of products sold; iii) less advertising, selling, general and administrative expenses; iv) less amortization of intangibles; and v) less restructuring charges.