Note 3 Fair Value (Narratives) (Details) (USD $)	12 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Auction Market Preferred Securities [Abstract]
Collateralized Asset Value Exceeding Value of ARPS Percentage	300.00%
Auction Rate Preferred Securities, Credit Ratings	AAA
Auction Rate Preferred Securities, Percentage Collateralized	100.00%
Debt, Long-term and Short-term, Combined Amount [Abstract]
Debt, Fair Value	$ 21,400,000	$ 23,400,000
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Auction Rate Preferred Securities	$ 350,000	$ 350,000

Aution rate preferred securities fair value as of the balance sheet date.

No definition available.

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Description of the credit rating of auction rate preferred securities given by a credit rating agency.

No definition available.

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Period Type:	duration

The percentage rate that the auction rate preferred securities are collaterized.

No definition available.

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Namespace Prefix:	ixys_
Data Type:	num:percentItemType
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Period Type:	duration

Collateralized asset value exceeding the value of ARPS in percentage.

No definition available.

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Namespace Prefix:	ixys_
Data Type:	num:percentItemType
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Period Type:	instant

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Represents the aggregate of total long-term debt, including current maturities and short-term debt.

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

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Data Type:	xbrli:stringItemType
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