FINANCIAL INSTRUMENTS: (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Mar. 31, 2012
Fair value of assets and liabilities
Other current assets	$ 52,750	$ 57,804
Other liabilities	4,178	4,455
Fair value measurements on recurring basis | Level 1
Fair value of assets and liabilities
Other current assets	13,394
Total assets	13,394
Other current liabilities	13,394
Total liabilities	13,394
Fair value measurements on recurring basis | Level 2
Fair value of assets and liabilities
Other liabilities	996
Total liabilities	996
Fair value measurements on recurring basis | Total fair value
Fair value of assets and liabilities
Other current assets	13,394
Total assets	13,394
Other current liabilities	13,394
Other liabilities	996
Total liabilities	$ 14,390