REVENUE AND MAJOR CUSTOMERS (Details)	3 Months Ended		12 Months Ended
	Jun. 27, 2020 USD ($) Customer	Jun. 29, 2019 USD ($) Customer	Mar. 28, 2020 USD ($) Customer
Revenue from External Customer [Line Items]
Contract with Customer, Asset, before Allowance for Credit Loss, Current	$ 3,000,000.0		$ 3,700,000
Revenue, Remaining Performance Obligation, Current	143,700
Net revenues	$ 355,720,000	$ 447,767,000
Revenue From Contracts With Customers, Percentage Associated With Non-cancellable Maintenance And Support Contracts	90.00%
Contract with Customer, Liability	$ 208,600,000		$ 208,500,000
Capitalized Contract Cost, Gross	4,600,000
Revenue, Remaining Performance Obligation, Noncurrent	66,800
Revenue, Remaining Performance Obligation, Amount	210,500
Contract with Customer, Liability, Revenue Recognized	72,400,000
Headset [Member]
Revenue from External Customer [Line Items]
Net revenues	174,750,000	218,650,000
Product
Revenue from External Customer [Line Items]
Net revenues	291,458,000	382,745,000
Product | United States
Revenue from External Customer [Line Items]
Net revenues	144,289,000	198,781,000
Product | Europe and Africa
Revenue from External Customer [Line Items]
Net revenues	77,618,000	101,106,000
Product | Asia Pacific
Revenue from External Customer [Line Items]
Net revenues	45,431,000	57,252,000
Product | Americas, excluding U.S.
Revenue from External Customer [Line Items]
Net revenues	24,120,000	25,606,000
Product | Total international net revenues [Member]
Revenue from External Customer [Line Items]
Net revenues	147,169,000	183,964,000
Voice
Revenue from External Customer [Line Items]
Net revenues	50,681,000	103,847,000
Video
Revenue from External Customer [Line Items]
Net revenues	66,027,000	60,248,000
Service
Revenue from External Customer [Line Items]
Net revenues	64,262,000	65,022,000
Service | United States
Revenue from External Customer [Line Items]
Net revenues	23,992,000	26,046,000
Service | Europe and Africa
Revenue from External Customer [Line Items]
Net revenues	16,488,000	15,873,000
Service | Asia Pacific
Revenue from External Customer [Line Items]
Net revenues	18,833,000	17,596,000
Service | Americas, excluding U.S.
Revenue from External Customer [Line Items]
Net revenues	4,949,000	5,507,000
Service | Total international net revenues [Member]
Revenue from External Customer [Line Items]
Net revenues	$ 40,270,000	$ 38,976,000
Net Revenues [Member] | Customer Concentration Risk [Member]
Revenue from External Customer [Line Items]
Number of Major Customers, Ten Percent Or Greater, Net Revenues | Customer	2	2
Net Revenues [Member] | Customer Concentration Risk [Member] | ScanSource [Member]
Revenue from External Customer [Line Items]
Concentration risk percentage	13.50%	17.40%
Net Revenues [Member] | Customer Concentration Risk [Member] | Ingram Micro [Member]
Revenue from External Customer [Line Items]
Concentration risk percentage	18.30%	16.90%
Accounts Receivable [Member] | Customer Concentration Risk [Member]
Revenue from External Customer [Line Items]
Number of major customers, ten percent or greater, net accounts receivable | Customer	2		3
Accounts Receivable [Member] | Customer Concentration Risk [Member] | ScanSource [Member]
Revenue from External Customer [Line Items]
Concentration risk percentage	19.00%		17.30%
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Ingram Micro [Member]
Revenue from External Customer [Line Items]
Concentration risk percentage	25.80%		22.20%
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Synnex Corp. [Member]
Revenue from External Customer [Line Items]
Concentration risk percentage			15.60%
Minimum [Member]
Revenue from External Customer [Line Items]
Revenue From Contracts With Customers, Credit Term	30 days
Maximum [Member]
Revenue from External Customer [Line Items]
Revenue From Contracts With Customers, Credit Term	90 days