FINANCIAL INSTRUMENTS: (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Mar. 31, 2013
Fair value of assets and liabilities
Other current assets	$ 60,052	$ 58,935
Fair value measurements on recurring basis | Level 1
Fair value of assets and liabilities
Other current assets	14,131
Total assets	14,131
Fair value measurements on recurring basis | Level 2
Fair value of assets and liabilities
Other accrued expenses	334
Total liabilities	334
Fair value measurements on recurring basis | Total
Fair value of assets and liabilities
Other current assets	14,131
Total assets	14,131
Other accrued expenses	334
Total liabilities	$ 334