FAIR VALUE MEASUREMENTS (Details) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 30, 2020 USD ($) $ / shares
Australian Dollar Forward Contracts | Cost of goods and services
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain reclassified for settled contracts	$ 556	$ 1,550
Designated as Hedging Instrument | Australian Dollar Forward Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset, notional amount	43,500	$ 43,500
Contracts weighted average rate price (in dollars per share) | $ / shares		$ 1.46
Deferred losses from currency translation included in AOCI	1,095	$ 1,095
Deferred losses from currency translation included in AOCI, net of tax	712	$ 712
Designated as Hedging Instrument | Australian Dollar Forward Contracts | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contracts duration		15 days
Designated as Hedging Instrument | Australian Dollar Forward Contracts | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contracts duration		209 days
Not Designated as Hedging Instrument | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contracts duration		2 days
Not Designated as Hedging Instrument | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contracts duration		328 days
Not Designated as Hedging Instrument | Canadian Dollar Forward Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset, notional amount	$ 3,125	$ 3,125
Derivative, average forward exchange rate	1.36	1.36
Not Designated as Hedging Instrument | British Pound Forward Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset, notional amount	$ 3,000	$ 3,000
Derivative, average forward exchange rate	0.81	0.81
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Insurance contracts fair value	$ 3,324	$ 3,324
Fair Value, Inputs, Level 2 | Other Income
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain (loss) on foreign currency derivative instruments not designated as hedging instruments	(222)	(23)
Fair Value, Inputs, Level 2 | Not Designated as Hedging Instrument | Other Income
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Realized gains (losses)	115	202
Fair Value, Inputs, Level 2 | Estimate of Fair Value Measurement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	3,028	3,028
Fair Value, Inputs, Level 2 | Portion at Other than Fair Value Measurement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	2,365	2,365
Senior notes due 2028 | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible debt, fair value disclosures	$ 980,000	$ 980,000