FAIR VALUE MEASUREMENTS (Details) - 3 months ended Dec. 31, 2019 $ / shares in Units, £ in Thousands, $ in Thousands, $ in Thousands	USD ($) $ / shares	GBP (£)	AUD ($)	USD ($)
Australian Dollar Forward Contracts | Cost of goods and services
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Losses recorded for settled contracts	$ 56
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			$ 20,000
Contracts weighted average rate price (in dollars per share) | $ / shares	$ 1.43
AOCI currency translation adjustment before tax				$ 202
AOCI currency translation adjustment after tax				$ 119
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	180 days
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 | £		£ 750
Contracts weighted average rate price (in dollars per share) | $ / shares	$ 0.76
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			$ 4,050
Derivative, average forward exchange rate		1.30	1.30	1.30
Not Designated as Hedging Instrument | Canadian Dollar Forward Contracts | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contracts duration	30 days
Not Designated as Hedging Instrument | Canadian Dollar Forward Contracts | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contracts duration	270 days
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Insurance contracts fair value				$ 3,445
Fair Value, Inputs, Level 2 | Not Designated as Hedging Instrument | Canadian Dollar Forward Contracts
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	$ 72
Fair Value, Inputs, Level 2 | Not Designated as Hedging Instrument | Canadian Dollar Forward Contracts | Other Income
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Realized gains (losses)	$ 3
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				2,835
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				2,236
Senior notes due 2022 | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible debt, fair value disclosures				$ 1,005,200