ALLOWANCE FOR DOUBTFUL ACCOUNTS: (Details) (Allowance for doubtful accounts, returns and credits, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Allowance for doubtful accounts, returns and credits
Allowance for doubtful accounts, returns and credits
Balance at beginning of period	$ 4,141	$ 4,876	$ 5,622
Additions charged to costs and expenses	1,058	902	1,731
Other changes	117	(112)	(164)
Bad debts written off, net of amounts recovered	(405)	(1,525)	(2,313)
Balance at end of period	$ 4,911	$ 4,141	$ 4,876