Summary of Significant Accounting Policies (Guarantees) (Details) - USD ($)	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Guarantees
Balance as of October 1	$ 29,700,000	$ 20,500,000
Balance as of September 30	30,800,000	29,700,000
Standard Product Warranty Accrual, Increase for Warranties Issued	18,600,000	23,000,000.0
Standard Product Warranty Accrual, Additions from Business Acquisition	0	200,000
Standard Product Warranty Accrual, Decrease for Payments	$ (17,500,000)	(16,800,000)
Warranty term, generally	1 year
Asset acquisition [Member]
Guarantees
Standard Product Warranty Accrual, Additions from Business Acquisition		$ 2,800,000