INCOME TAXES - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Income Tax Contingency [Line Items]
Income tax benefit	$ 1,071	$ 1,441
Effective tax rate	16.00%	83.00%
Blended tax rate	24.50%
Re-measurement of deferred tax assets	$ 700
Valuation allowance	200
Research And Development Tax Credit
Income Tax Contingency [Line Items]
Release of Fin 48 reserve relating to Research and Development Tax Credit	$ 300