SIGNIFICANT ACCOUNTING POLICIES (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Jun. 30, 2017 USD ($)	Mar. 31, 2018 USD ($) Customer	Mar. 31, 2017 USD ($) Customer	Mar. 31, 2016 USD ($)	Mar. 31, 2015	May 31, 2015
Product Information [Line Items]
Duration of fiscal year		364 days	371 days	364 days	364 days
Loss on sale of long-term investments		$ 1,200
Unconditional purchase obligations		190,000
Off-balance sheet consigned inventory		48,800	$ 52,300
Advertising expense		$ 900	$ 1,800	$ 2,000
Number of customers accounting for 10% or more of net accounts receivable | Customer		2	1
Income tax expense		$ 101,096	$ 19,066	$ 13,784
Minimum
Product Information [Line Items]
Product warranty terms		1 year
Maximum
Product Information [Line Items]
Product warranty terms		2 years
Customer concentration risk | Accounts receivable
Product Information [Line Items]
Concentration risk percentage			17.60%
5.50% Senior Notes | Senior notes
Product Information [Line Items]
Stated interest rate		5.50%				5.50%
Out-of-Period Error Resulting in Overstatement of Income Tax Expense
Product Information [Line Items]
Income tax expense	$ (2,800)
Out-of-Period Error Resulting in Overstatement of Income Tax Expense | Restatement Adjustment
Product Information [Line Items]
Income tax expense			$ 2,800
D & H Distributing | Customer concentration risk | Accounts receivable
Product Information [Line Items]
Concentration risk percentage		13.00%
Ingram Micro | Customer concentration risk | Accounts receivable
Product Information [Line Items]
Concentration risk percentage		12.40%