FINANCIAL INSTRUMENTS: (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Mar. 31, 2013
Fair value of assets and liabilities
Other current assets	$ 55,955	$ 58,935
Fair value measurements on recurring basis | Level 1
Fair value of assets and liabilities
Other current assets	13,374
Total assets	13,374
Fair value measurements on recurring basis | Level 2
Fair value of assets and liabilities
Other accrued expenses	554
Total liabilities	554
Fair value measurements on recurring basis | Total fair value
Fair value of assets and liabilities
Other current assets	13,374
Total assets	13,374
Other accrued expenses	554
Total liabilities	$ 554