FAIR VALUE OF FINANCIAL INSTRUMENTS: (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Mar. 31, 2011
Fair value of assets and liabilities
Other current assets	$ 57,804	$ 55,668
Other non current liabilities	4,455	7,478
Fair value measurements on recurring basis | Level 1
Fair value of assets and liabilities
Other current assets	13,344
TOTAL ASSETS	13,344
Other current liabilities	13,344
Other non current liabilities	0
Total liabilities	13,344
Fair value measurements on recurring basis | Level 2
Fair value of assets and liabilities
Other current assets	0
TOTAL ASSETS	0
Other current liabilities	0
Other non current liabilities	1,063
Total liabilities	1,063
Fair value measurements on recurring basis | Total fair value
Fair value of assets and liabilities
Other current assets	13,344
TOTAL ASSETS	13,344
Other current liabilities	13,344
Other non current liabilities	1,063
Total liabilities	$ 14,407