FINANCIAL INSTRUMENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018
Debt Securities, Available-for-sale [Line Items]
Cash - As Restated	$ 2,237		$ 6,467
Adjusted Cost			78,027
Unrealized Gains			247
Fair Value			78,274
Cash and Cash Equivalents	58,812	$ 32,415	16,596	$ 40,663
Short-term Marketable Securities	$ 0	$ 40,885	61,678	$ 55,480
U.S. Treasury Securities, maturities less than three months
Debt Securities, Available-for-sale [Line Items]
Adjusted Cost			10,129
Fair Value			10,129
Cash and Cash Equivalents			10,129
U.S. Treasury Securities, maturities greater than three months
Debt Securities, Available-for-sale [Line Items]
Adjusted Cost			61,431
Unrealized Gains			247
Fair Value			61,678
Short-term Marketable Securities			$ 61,678