COMMITMENTS AND CONTINGENCIES (Details) - USD ($)		1 Months Ended	12 Months Ended
	Dec. 10, 2018	Jul. 31, 2016	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2018
Operating Leases, Future Minimum Payments Due [Abstract]
2020						$ 18,882,000
2021						17,883,000
2022						15,239,000
2023						5,800,000
2024						$ 1,281,000
Thereafter			$ 601,000
Total minimum future rental payments			59,686,000
2020			(5,238,000)
2021			(5,481,000)
2022			(5,645,000)
2023			(1,160,000)
2024			0
Thereafter			0
Total minimum future rental payments			17,524,000
2020			13,644,000
2021			12,402,000
2022			9,594,000
2023			4,640,000
2024			1,281,000
Thereafter			601,000
Total minimum future rental payments			42,162,000
Unconditional purchase obligations			399,000,000
Loss Contingencies [Line Items]
Operating Leases, Rent Expense			17,800,000	$ 2,600,000	$ 2,800,000
Litigation Settlement, Amount Awarded to Other Party	$ 374,475		38,100,000
Litigation Settlement, Disgorgement, Amount Awarded to Other Party			31,000,000
Litigation Settlement, Prejudgement Interest, Amount Awarded to Other Party			1,800,000
Litigation Settlement, Civil Penalties, Amount Awarded to Other Party			3,800,000
Litigation Settlement, Reimbursement Of Legal Fees			1,400,000
GN Netcom, Inc. vs. Plantronics, Inc. | Punitive Sanctions
Loss Contingencies [Line Items]
Punitive sanctions awarded against Plantronics, Inc.		$ 4,900,000
Litigation Settlement, Amount Awarded from Other Party			$ 200,000