Summary of Significant Accounting Policies Revenue Recognition - Impact on Income Statement (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenue	$ 692.5	$ 566.9
Cost of goods sold	448.3	395.1
Gross profit	244.2	171.8
Operating expenses	131.6	157.4
Income before income taxes	109.0	(13.2)
Income tax expense (benefit)	31.3	(12.4)
Consolidated net income (loss)	$ 77.7	$ (0.8)