INCOME TAX EXPENSE (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Expense [Line Items]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	24.50%	35.00%
Effective Income Tax Provisional Charge Transition Tax	$ 3,700
Income Tax Expense (Benefit)	$ 5,940	$ (21,870)
Effective Income Tax Rate Reconciliation, Percent	25.50%	170.80%
Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Percent	18.30%
Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Amount	$ 2,300
Effective Income Tax Rate Reconciliation, Tax Settlement, Domestic, Percent	22.80%
Effective Income Tax Rate Reconciliation, Tax Settlement, Domestic, Amount	$ 2,900
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent	236.80%
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount	$ 30,300
Effective Income Tax Rate Reconciliation, Other Adjustments, Percent	1.30%
Tax Cuts And Jobs Act [Member]
Income Tax Expense [Line Items]
Income Tax Expense (Benefit)	$ 25,100