INCOME TAXES: - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2020	Apr. 01, 2020	Mar. 31, 2019
Income Tax Examination [Line Items]
Deferred tax assets, valuation allowance	$ 32,971		$ 34,356
Gross unrecognized tax benefits that would impact effective tax rate	23,400
Accrued interest and penalties related to tax positions on tax returns	2,500
Increase in accrued interest and penalties related to tax positions on tax returns	2,100
Scenario, Forecast
Income Tax Examination [Line Items]
Income tax examination, liability (refund) adjustment from settlement with taxing authority		$ (32,000)
Internal Revenue Service (IRS)
Income Tax Examination [Line Items]
Operating loss carryforwards	21,700
Federal tax authority
Income Tax Examination [Line Items]
State credit carryforwards that will not expire	11,500
State and Local Jurisdiction
Income Tax Examination [Line Items]
Operating loss carryforwards	70,000
State credit carryforwards that will not expire	9,500
Tax credit carryforward, amount	2,100
Foreign Tax Authority
Income Tax Examination [Line Items]
Operating loss carryforwards	99,900
Deferred tax assets, valuation allowance	26,600
Indefinite Tax Year | Foreign Tax Authority
Income Tax Examination [Line Items]
Operating loss carryforwards	$ 93,300