FINANCIAL INSTRUMENTS: (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Mar. 31, 2016
Fair value of assets and liabilities
Other current assets	$ 48,310	$ 37,897
Fair value measurements on recurring basis
Fair value of assets and liabilities
Other current assets	12,716	12,532
Total assets	12,716	12,532
Other accrued expenses		115
Total liabilities		115
Fair value measurements on recurring basis | Level 1
Fair value of assets and liabilities
Other current assets	12,716	12,532
Total assets	$ 12,716	12,532
Fair value measurements on recurring basis | Level 2
Fair value of assets and liabilities
Other accrued expenses		115
Total liabilities		$ 115