Basis Of Presentation And Significant Accounting Policies (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018	Dec. 30, 2018	Oct. 01, 2018	Sep. 30, 2018
Significant Accounting Policies [Line Items]
Volume-based arrangement period			12 months
Expected returns from customers	$ 40.5		$ 40.5				$ 34.6
Practical Expedients and Exemptions			Practical Expedients and ExemptionsThe Company accounts for shipping and handling activities which occur after control of the related goods transfers as fulfillment activities instead of assessing such activities as performance obligations. The use of the practical expedient did not impact the accounting for the adoption of Topic 606.The Company does not adjust the promised amount of consideration for the effects of a significant financing component, as the period between the transfer of a promised good or service to a customer and the customer's payment for the good or service is one year or less.The Company does not assess whether promised goods or services are performance obligations if they are immaterial in the context of the contract with the customer. The Company does not disclose the value of unsatisfied performance obligations for (i) contracts with an original expected length of one year or less and (ii) contracts for which we recognize revenue at the amount to which we have the right to invoice for services performed. The estimated revenue expected to be recognized in the future related to performance obligations that are unsatisfied or partially unsatisfied at the end of the reporting period is immaterial.The Company generally expenses sales commissions and other contract and fulfillment costs when the amortization period is less than one year. The Company records these costs within selling, general and administrative expenses. For costs amortized over a period longer than one year, such as fixtures which are much more permanent in nature, the Company defers and amortizes over the supportable period based upon historical assumptions and analysis. The costs for permanent displays are incorporated into the pricing of product sold to customer.The Company excludes all sales taxes that are assessed by a governmental authority from the transaction price.
Cumulative adjustment for adoption of new accounting standards					$ 3.2
Error In Income From Discontinued Operations Related To Depreciation And Amortization [Member]
Significant Accounting Policies [Line Items]
Error in cumulative impact from adoption		$ 13.2		$ 13.2
Error In Adoption On Deferred Tax Assets [Member]
Significant Accounting Policies [Line Items]
Error in cumulative impact from adoption	30.7
Accounting Standards Update 2014-09 [Member]
Significant Accounting Policies [Line Items]
Cumulative adjustment for adoption of new accounting standards						$ 0.7
Accounting Standards Update 2016-16 [Member]
Significant Accounting Policies [Line Items]
Cumulative adjustment for adoption of new accounting standards						$ 2.4
Accounting Standards Update 2016-18 [Member] | Prepaid Expenses and Other Current Assets [Member]
Significant Accounting Policies [Line Items]
Restricted cash	$ 8.9		$ 8.9				$ 8.9