Details of Certain Balance Sheet Accounts (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Dec. 31, 2011	Mar. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable	$ 131,249	$ 125,137
Accounts receivable, net	109,677	103,289
Inventory, net [Abstract]
Raw materials	15,374	15,315
Work in process	2,815	2,558
Finished goods	39,610	38,600
Inventory, Net	57,799	56,473
Accrued Liabilities [Abstract]
Employee compensation and benefits	22,969	27,478
Warranty obligation accrual	13,509	11,016
Accrued advertising and sales and marketing	1,810	2,873
Accrued other	12,506	18,240
Accrued liabilities	50,794	59,607
Movement in Standard Product Warranty Accrual [Roll Forward]
Warranty obligation accrual at March 31, 2011	11,016
Warranty provision relating to products shipped	13,261
Deductions for warranty claims processed	(10,768)
Warranty obligation accrual at December 31, 2011	13,509
Provision For Returns [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable Reserves	(8,050)	(10,437)
Provision For Promotions, Rebates And Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable Reserves	(13,011)	(10,460)
Provision For Doubtful Accounts And Sales Allowances [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable Reserves	$ (511)	$ (951)