REVENUE AND MAJOR CUSTOMERS (Details)	3 Months Ended								12 Months Ended
	Apr. 03, 2021 USD ($)	Dec. 26, 2020 USD ($)	Sep. 26, 2020 USD ($)	Jun. 27, 2020 USD ($)	Mar. 28, 2020 USD ($) Customer	Dec. 28, 2019 USD ($)	Sep. 28, 2019 USD ($)	Jun. 29, 2019 USD ($)	Apr. 03, 2021 USD ($) Customer	Mar. 28, 2020 USD ($) Customer	Mar. 30, 2019 USD ($) Customer	Mar. 31, 2019 Customer
Revenue from External Customer [Line Items]
Contract with Customer, Asset, Gross, Current	$ 4,100,000				$ 3,700,000				$ 4,100,000	$ 3,700,000
Revenue, Remaining Performance Obligation, Current	141,400								141,400
Net revenues	476,233,000	$ 484,685,000	$ 410,969,000	$ 355,720,000	403,043,000	$ 384,471,000	$ 461,709,000	$ 447,767,000	1,727,607,000	1,696,990,000	$ 1,674,535,000
Contract with Customer, Liability	213,800,000				$ 208,500,000				$ 213,800,000	$ 208,500,000
Contract with Customer, Liability, Percentage Of Revenue									12.40%	12.30%
Number of major customers, ten percent or greater, net accounts receivable | Customer												1
Capitalized Contract Cost, Gross	4,900,000								$ 4,900,000
Revenue, Remaining Performance Obligation, Noncurrent	72,400								72,400
Revenue, Remaining Performance Obligation, Amount	$ 213,800								213,800
Contract with Customer, Liability, Revenue Recognized									144,100,000
Capitalized Contract Cost, Amortization									2,300,000
Product
Revenue from External Customer [Line Items]
Net revenues									1,470,826,000	$ 1,432,736,000	1,510,770,000
Product | U.S.
Revenue from External Customer [Line Items]
Net revenues									647,321,000	708,566,000	729,930,000
Product | Europe and Africa
Revenue from External Customer [Line Items]
Net revenues									512,196,000	398,721,000	432,899,000
Product | Asia Pacific
Revenue from External Customer [Line Items]
Net revenues									208,597,000	221,912,000	245,499,000
Product | Americas, excluding U.S.
Revenue from External Customer [Line Items]
Net revenues									102,712,000	103,537,000	102,442,000
Product | Total international net revenues [Member]
Revenue from External Customer [Line Items]
Net revenues									823,505,000	724,170,000	780,840,000
Enterprise Headset [Member]
Revenue from External Customer [Line Items]
Net revenues									823,451,000	773,186,000	910,699,000
Voice
Revenue from External Customer [Line Items]
Net revenues									221,131,000	375,505,000	344,586,000
Video
Revenue from External Customer [Line Items]
Net revenues									426,244,000	284,045,000	255,485,000
Service
Revenue from External Customer [Line Items]
Net revenues									256,781,000	264,254,000	163,765,000
Service | U.S.
Revenue from External Customer [Line Items]
Net revenues									96,548,000	102,103,000	59,615,000
Service | Europe and Africa
Revenue from External Customer [Line Items]
Net revenues									64,660,000	66,900,000	43,991,000
Service | Asia Pacific
Revenue from External Customer [Line Items]
Net revenues									77,158,000	73,424,000	43,382,000
Service | Americas, excluding U.S.
Revenue from External Customer [Line Items]
Net revenues									18,415,000	21,827,000	16,777,000
Service | Total international net revenues [Member]
Revenue from External Customer [Line Items]
Net revenues									$ 160,233,000	$ 162,151,000	$ 104,150,000
Net Revenues [Member] | Customer concentration risk
Revenue from External Customer [Line Items]
Number of major customers, ten percent or greater, net revenues | Customer									2	2	2
Net Revenues [Member] | Customer concentration risk | Ingram Micro [Member]
Revenue from External Customer [Line Items]
Concentration risk percentage									19.30%	17.30%	11.40%
Net Revenues [Member] | Customer concentration risk | ScanSource [Member]
Revenue from External Customer [Line Items]
Concentration risk percentage									19.00%	19.80%	16.00%
Accounts receivable | Customer concentration risk
Revenue from External Customer [Line Items]
Number of major customers, ten percent or greater, net accounts receivable | Customer					3					3
Accounts receivable | Customer concentration risk | Ingram Micro [Member]
Revenue from External Customer [Line Items]
Concentration risk percentage									24.70%	22.20%	22.20%
Accounts receivable | Customer concentration risk | Scansource, D&H Distributors And Ingram Micro [Member]
Revenue from External Customer [Line Items]
Number of major customers, ten percent or greater, net accounts receivable | Customer											3
Accounts receivable | Customer concentration risk | ScanSource [Member]
Revenue from External Customer [Line Items]
Concentration risk percentage									24.90%	17.30%	17.30%
Accounts receivable | Customer concentration risk | Synnex Corp. [Member]
Revenue from External Customer [Line Items]
Concentration risk percentage										15.60%	15.60%
Minimum
Revenue from External Customer [Line Items]
Revenue From Contracts With Customers, Credit Term									30 years
Maximum
Revenue from External Customer [Line Items]
Revenue From Contracts With Customers, Credit Term									90 years