FINANCIAL INSTRUMENTS: (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Mar. 31, 2016
Fair value of assets and liabilities
Other current assets	$ 48,035	$ 37,897
Fair value measurements on recurring basis | Level 1
Fair value of assets and liabilities
Other current assets	12,443
Total assets	12,443
Fair value measurements on recurring basis | Level 2
Fair value of assets and liabilities
Other accrued expenses	(2)
Total liabilities	(2)
Fair value measurements on recurring basis | Total
Fair value of assets and liabilities
Other current assets	12,443
Total assets	12,443
Other accrued expenses	(2)
Total liabilities	$ (2)