DETAILS OF CERTAIN BALANCE SHEET ACCOUNTS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013		Mar. 31, 2014
Accounts receivable, net [Line Items]
Accounts receivable	$ 182,103		$ 182,103			$ 159,592
Accounts receivable, net	157,322		157,322			138,301
Inventory, net [Abstract]
Raw materials	26,385		26,385			28,071
Work in process	1,609		1,609			985
Finished goods	29,730		29,730			28,076
Inventory, net	57,724		57,724			57,132
Accrued Liabilities [Abstract]
Employee compensation and benefits	33,844		33,844			32,280
Warranty obligation	8,324	7,963	8,324	7,963
Income taxes payable	0		0			3,092
Accrued other	23,430		23,430			23,514
Accrued liabilities	65,598		65,598			66,851
Changes in the Warranty Obligation [Roll Forward]
Warranty obligation at beginning of period			7,965	13,410
Warranty provision related to products shipped			7,880	7,234
Deductions for warranty claims processed			(6,960)	(7,272)
Adjustments related to preexisting warranties			(561)	(5,409)	[1]
Warranty obligation at end of period	8,324	7,963	8,324	7,963
Warranty obligation correction	8,324	7,963	8,324	7,963
Cost of revenues	111,865	102,412	311,795	293,964
Net income	30,384	34,383	86,477	84,474
Provisions for returns [Member]
Accounts receivable, net [Line Items]
Accounts receivable, reserves	(7,623)		(7,623)			(6,201)
Provisions for promotions, rebates, and other [Member]
Accounts receivable, net [Line Items]
Accounts receivable, reserves	(15,934)		(15,934)			(14,803)
Provisions for doubtful accounts and sales allowances [Member]
Accounts receivable, net [Line Items]
Accounts receivable, reserves	(1,224)		(1,224)			(287)
Error related to estimated warranty obligation [Member] | Correcting adjustment [Member]
Accrued Liabilities [Abstract]
Warranty obligation		5,000		5,000
Changes in the Warranty Obligation [Roll Forward]
Warranty obligation at end of period		5,000		5,000
Warranty obligation correction		5,000		5,000
Cost of revenues		(2,400)
Net income		$ 2,100

[1] During the third quarter of fiscal 2014, the Company identified an immaterial out of period error related to its estimated warranty obligation. The Company recorded a $5.0 million correction in the quarter ended December 31, 2013 which decreased its cost of revenues by approximately $2.4 million and increased net income by approximately $2.1 million.