Summary of Significant Accounting Policies (Tables)

12 Months Ended

Sep. 30, 2020

Accounting Policies [Abstract]

Summary of depreciable lives of property, plant and equipment

Buildings	10 - 40 years
Computer equipment and software	3 - 7 years
Machinery and equipment	2 - 10 years
Furniture and fixtures	3 - 10 years

Summary of amortizable lives of finite-lived intangible assets

Patents	7 - 15 years
Completed technology	3 - 15 years
Customer relationships	3 - 14 years

Summary of stock-based compensation expense

	Year Ended September 30,
	2020		2019		2018
Restricted stock units	$	14,818	$	18,276	$	18,081
Employee stock purchase plan		1,499		1,203		775
Total stock-based compensation expense	$	16,317	$	19,479	$	18,856

Summary of valuation assumptions for an employee stock purchase plan

	Year Ended September 30,
	2020		2019		2018
Risk-free interest rate	0.9	%	2.3	%	1.9	%
Volatility	58	%	52	%	46	%
Expected life	6 months		6 months		6 months
Dividend yield	1.1	%	1.2	%	1.5	%