SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Provision for doubtful accounts and sales allowances
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	$ 1,093	$ 951	$ 2,279
Charged to Expenses or Other Accounts	468	758	(8)
Deductions	(1,152)	(616)	(1,320)
Balance at End of Year	409	1,093	951
Provision for returns
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	7,613	10,437	13,812
Charged to Expenses or Other Accounts	21,111	16,660	21,910
Deductions	(19,767)	(19,484)	(25,285)
Balance at End of Year	8,957	7,613	10,437
Provision for promotions and rebates
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	12,756	10,460	13,780
Charged to Expenses or Other Accounts	33,343	34,170	36,885
Deductions	(32,424)	(31,874)	(40,205)
Balance at End of Year	13,675	12,756	10,460
Inventory reserves
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	5,712	7,423	12,044
Charged to Expenses or Other Accounts	1,089	2,154	1,083
Deductions	(2,026)	(3,865)	(5,704)
Balance at End of Year	4,775	5,712	7,423
Warranty obligation
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	13,346	11,016	11,006
Charged to Expenses or Other Accounts	16,287	17,061	14,769
Deductions	(16,223)	(14,731)	(14,759)
Balance at End of Year	13,410	13,346	11,016
Valuation allowance for deferred tax assets
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	6,088	5,274	1,399
Charged to Expenses or Other Accounts	89	1,259	4,659
Deductions	(193)	(445)	(784)
Balance at End of Year	$ 5,984	$ 6,088	$ 5,274