Restructuring and Other Costs, Net - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Restructuring Cost and Reserve [Line Items]
Restructuring charges (reversal)	$ 2,870	$ 4,329	$ 10,424	$ 7,456
Severance Charge
Restructuring Cost and Reserve [Line Items]
Restructuring charges (reversal)	321	220	681	(443)
Professional Services Fees
Restructuring Cost and Reserve [Line Items]
Restructuring charges (reversal)	$ 2,549	4,490	$ 9,743	6,225
Facilities Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring charges (reversal)		$ (381)		$ 1,674