Income Taxes Tax Rate Reconciliation (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Income Tax Expense (Benefit), Income Tax Reconciliation [Abstract]
Federal income tax rate	34.00%	34.00%	34.00%
Tax benefit computed at statutory rates	$ (7,579)	$ (1,851)	$ (682)
State taxes, net of federal benefit	(1,672)	(419)	(168)
Research credits	(454)	(480)	(786)
Non-deductible expenses	133	130	113
Tax exempt income	(56)	(158)	(154)
Unrecognized tax benefits	83	(315)	337
Meals and entertainment	75	70	66
Foreign tax rate differences	(81)	(53)	(77)
Change in valuation allowance	10,052	4,002	150
Purchase accounting adjustment	0	0	(42)
Adjustment to deferred income tax rate	59	39	0
Other	284	30	2
Income tax expense (benefit)	$ 844	$ 995	$ (1,241)

Income Tax Reconciliation, Purchase Accounting Adjustment

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The domestic federal statutory tax rate applicable under enacted tax laws to the Company's pretax income from continuing operations for the period. The "statutory" tax rate is the regular tax rate if there are alternative tax systems.

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The sum of the current income tax expense or benefit and the deferred income tax expense or benefit pertaining to continuing operations.

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- Definition

The portion of the difference between total income tax expense or benefit as reported in the Income Statement and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations attributable to changes in the valuation allowance for deferred tax assets in the period.

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The portion of the difference between total income tax expense or benefit as reported in the Income Statement and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations, that is attributable to changes in the income tax rates under enacted tax laws in the period.

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The portion of the difference, between total income tax expense or benefit as reported in the Income Statement for the period and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations, that is attributable to total foreign income tax expense or benefit. The foreign income tax expense or benefit difference represents the income tax expense or benefit at applicable domestic statutory income tax rates applied to foreign earnings or loss for the period versus the foreign income tax expense or benefit calculated by applying the appropriate foreign tax rates.

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The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations.

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The portion of the difference between total income tax expense or benefit as reported in the Income Statement for the period and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations attributable to nondeductible expenses under enacted tax laws, or differences in the methodologies used to determine expense amounts for financial statements prepared in accordance with generally accepted accounting principles, not otherwise listed in the existing taxonomy.

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The portion of the difference, between total income tax expense or benefit as reported in the Income Statement for the year/accounting period and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations, that is attributable to all other items not otherwise listed in the existing taxonomy.

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The sum of the differences between total income tax expense or benefit as reported in the Income Statement and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations attributable to changes in all income tax contingencies, whether recorded or adjusted, during the period.

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The portion of the difference between total income tax expense or benefit as reported in the Income Statement and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations attributable to research tax credits generated or utilized under enacted tax laws during the period.

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