ALLOWANCE FOR DOUBTFUL ACCOUNTS: (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Allowance for doubtful accounts, returns and credits
Effects of exchange rates	$ 100
Gain on disposition of Impact email business	(300)
Allowance For Doubtful Accounts Returns And Credits
Allowance for doubtful accounts, returns and credits
Balance at beginning of period	7,262	$ 4,423	$ 4,875
Additions charged to costs and expenses	1,859	3,673	731
Other changes	(372)	56	(288)
Bad debts written off, net of amounts recovered	(2,643)	(890)	(895)
Balance at end of period	$ 6,106	$ 7,262	$ 4,423