Restructuring Expenses - Additional Information (Details)	3 Months Ended		6 Months Ended
	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Mar. 31, 2020 USD ($) position	Mar. 31, 2019 USD ($)
Restructuring Cost and Reserve [Line Items]
Expense Additions	$ 0	$ 0	$ 3,104,000	$ 0
Number of positions eliminated | position			69
Facilities charges
Restructuring Cost and Reserve [Line Items]
Expense Additions			$ 0
Employee separation
Restructuring Cost and Reserve [Line Items]
Expense Additions			$ 3,104,000