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Summary of Significant Accounting Policies (Narrative) (Details) - USD ($) $ in Millions		3 Months Ended		12 Months Ended
	Jan. 01, 2018	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Sep. 30, 2016
Summary Of Significant Accounting Policies [Line Items]
Additional net revenue and SGA expense			$ 2.5	$ 12.7
Sale of accounts receivable		$ 55.6
Accounts receivable available to be sold, maximum		150.0
Accounts receivable, net		55.6
Allowance for doubtful accounts receivable		19.8		19.7	$ 12.4
Shipping and handling costs		23.6	$ 24.7
Contract liability		25.7		$ 20.9
Revenue recognized		$ 9.6
Accounts Receivable [Member] | Customer A [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage		11.00%	17.00%	12.00%
Accounting Standards Update 2014-09 [Member]
Summary Of Significant Accounting Policies [Line Items]
Cumulative effect on retained earnings	$ 3.5

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