ALLOWANCE FOR DOUBTFUL ACCOUNTS: (Details) - Allowance for doubtful accounts, returns and credits - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Allowance for doubtful accounts, returns and credits
Balance at beginning of period	$ 4,423	$ 4,875	$ 4,105
Additions charged to costs and expenses	3,673	731	1,058
Other changes	56	(288)	117
Bad debts written off, net of amounts recovered	(890)	(895)	(405)
Balance at end of period	$ 7,262	$ 4,423	$ 4,875