Derivative Financial Instruments - Schedule of Notional Amounts of Outstanding Forward Contracts and Options (Details) - Not Designated as Hedging Instrument - Foreign Exchange Forward Contract and Options - USD ($) $ in Thousands	Mar. 31, 2021	Sep. 30, 2020
Derivative [Line Items]
Notional amount	$ 622,286	$ 512,462
Canadian / U.S. Dollar
Derivative [Line Items]
Notional amount	5,824	6,847
Euro / U.S. Dollar
Derivative [Line Items]
Notional amount	532,906	390,673
British Pound / U.S. Dollar
Derivative [Line Items]
Notional amount	1,459	6,328
Israeli Shekel / U.S. Dollar
Derivative [Line Items]
Notional amount	10,115	9,503
Japanese Yen / U.S. Dollar
Derivative [Line Items]
Notional amount	10,186	50,379
Swiss Franc / U.S. Dollar
Derivative [Line Items]
Notional amount	2,327	12,874
Swedish Krona / U.S. Dollar
Derivative [Line Items]
Notional amount	25,564	18,871
Chinese Renminbi / U.S. Dollar
Derivative [Line Items]
Notional amount	12,523	5,415
Taiwanese Dollar / U.S. Dollar
Derivative [Line Items]
Notional amount	7,876	1,482
All other
Derivative [Line Items]
Notional amount	$ 13,506	$ 10,090