ACQUISITIONS: - Other Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Amortization activity of purchased intangible assets
Intangible assets, gross	$ 119,114	$ 78,316	$ 76,690
Accumulated amortization	(52,855)	(34,213)	(21,189)
Total	66,259	44,103	55,501
Amortization expense	18,600	15,500	11,400
Developed technology.
Amortization activity of purchased intangible assets
Amortization expense	$ 27,500	$ 30,700	$ 29,000