Income Taxes (Details 1)	12 Months Ended
Mar. 31, 2011 USD ($)	Mar. 31, 2010	Mar. 31, 2009	Mar. 31, 2011 JPY (¥)	Mar. 31, 2010 JPY (¥)
Net deferred tax assets and liabilities
Deferred income taxes and other current assets	$ 674,132,000			¥ 55,953,000,000	¥ 43,390,000,000
Deferred income taxes and other assets	182,133,000			15,117,000,000	36,467,000,000
Deferred income taxes and other current liabilities	(4,578,000)			(380,000,000)	(128,000,000)
Deferred income taxes and other liabilities	(211,988,000)			(17,595,000,000)	(16,836,000,000)
Net deferred tax assets and liabilities	639,699,000			53,095,000,000	62,893,000,000
Differences between the Japanese statutory tax rates and the effective tax rates
Japanese statutory tax rate	40.80%	40.80%	40.80%
Increase (decrease) in tax rates resulting from:
Change in valuation allowance	(4.50%)	25.20%	7.10%
Expenses not deductible for tax purposes	1.50%	6.80%	2.90%
Realization of tax benefits on operating losses of subsidiaries	(0.40%)	(0.80%)	(1.40%)
Income of foreign subsidiaries taxed at lower than Japanese normal rate	(8.30%)	(22.60%)	(11.30%)
Tax credit for research and development expenses	(1.30%)		(0.70%)
Realization of loss for investment in a subsidiary		(10.20%)
Other, net	1.60%	(0.20%)	(4.60%)
Effective tax rate	29.40%	39.00%	32.80%
Period available to offset future taxable income varies in each tax jurisdiction
Within 5 years				43,415,000,000
6 to 20 years				36,632,000,000
Indefinite periods				14,550,000,000
Total	$ 1,139,722,000			¥ 94,597,000,000

Effective Income Tax Rate Reconciliation Realization of loss for investment in a subsidiary.

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Effective Income Tax Rate Reconciliation Realization of tax benefits on operating losses of subsidiaries.

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Increase (decrease) in tax rates resulting from.

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Operating loss carry forwards to be offset in indefinite period.

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Operating Loss Carry forwards To be offset Within Five Year.

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Operating Loss Carry forwards To be offset Within Six To Twenty Years.

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Period available to offset future taxable income varies in each tax jurisdiction.

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For entities that net deferred tax assets and tax liabilities, represents the unclassified net amount of deferred tax assets and liabilities as of the balance sheet date, which result from applying the applicable enacted tax rate to net temporary differences and carryforwards pertaining to assets or liabilities. A temporary difference is a difference between the tax basis of an asset or liability and its carrying amount in the financial statements prepared in accordance with generally accepted accounting principles that will reverse in ensuing periods.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 42, 43

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For entities that net deferred tax assets and tax liabilities, represents the net amount of deferred tax assets (after reduction for valuation allowance) and liabilities as of the balance sheet date, which result from applying the applicable enacted tax rate to net temporary differences and carryforwards pertaining to assets or liabilities that are classified as current in the financial statements, or that are expected to reverse in the next twelve months (or normal operating cycle, if longer). A temporary difference is a difference between the tax basis of an asset or liability and its carrying amount in the financial statements prepared in accordance with generally accepted accounting principles that will reverse in ensuing periods. In a classified statement of financial position, an enterprise shall separate deferred tax liabilities and assets into a current amount and a noncurrent amount. Deferred tax liabilities and assets shall be classified as current or noncurrent based on the classification of the related asset or liability for financial reporting. A deferred tax liability or asset that is not related to an asset or liability for financial reporting, including deferred tax assets related to carryforwards, shall be classified according to the expected reversal date of the temporary difference.

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For entities that net deferred tax assets and tax liabilities, represents the net amount of deferred tax assets (after reduction for valuation allowance) and liabilities as of the balance sheet date, which result from applying the applicable enacted tax rate to net temporary differences and carryforwards pertaining to assets or liabilities that are classified as noncurrent in the financial statements, or that are expected to reverse after the next twelve months (or beyond the normal operating cycle, if longer). A temporary difference is a difference between the tax basis of an asset or liability and its carrying amount in the financial statements prepared in accordance with generally accepted accounting principles that will reverse in ensuing periods. In a classified statement of financial position, an enterprise shall separate deferred tax liabilities and assets into a current amount and a noncurrent amount. Deferred tax liabilities and assets shall be classified as current or noncurrent based on the classification of the related asset or liability for financial reporting. A deferred tax liability or asset that is not related to an asset or liability for financial reporting, including deferred tax assets related to carryforwards, shall be classified according to the expected reversal date of the temporary difference.

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The current portion of the aggregate tax effects as of the balance sheet date of all future tax deductions arising from temporary differences between tax basis and generally accepted accounting principles basis recognition of assets, liabilities, revenues and expenses, which can only be deducted for tax purposes when permitted under enacted tax laws; after deducting the allocated valuation allowance, if any, to reduce such amount to net realizable value. Deferred tax liabilities and assets shall be classified as current or noncurrent based on the classification of the related asset or liability for financial reporting. A deferred tax liability or asset that is not related to an asset or liability for financial reporting, including deferred tax assets related to carryforwards, shall be classified according to the expected reversal date of the temporary difference. An unrecognized tax benefit that is directly related to a position taken in a tax year that results in a net operating loss carryforward should be presented as a reduction of the related deferred tax asset.

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-Name Statement of Financial Accounting Standard (FAS)
-Number 109
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The noncurrent portion as of the balance sheet date of the aggregate carrying amount of all future tax deductions arising from temporary differences between tax basis and generally accepted accounting principles basis recognition of assets, liabilities, revenues and expenses, which can only be deducted for tax purposes when permitted under enacted tax laws; after the valuation allowance, if any, to reduce such amount to net realizable value. Deferred tax liabilities and assets shall be classified as current or noncurrent based on the classification of the related asset or liability for financial reporting. A deferred tax liability or asset that is not related to an asset or liability for financial reporting, including deferred tax assets related to carryforwards, shall be classified according to the expected reversal date of the temporary difference.

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A ratio calculated by dividing the reported amount of income tax expense attributable to continuing operations for the period by GAAP-basis pretax income from continuing operations.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Name Regulation S-X (SX)
-Number 210
-Section 08
-Paragraph h
-Subparagraph 2
-Article 4

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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 shall be the regular tax rate if there are alternative tax systems.

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The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate attributable to changes in the valuation allowance for deferred tax assets.

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The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate that can be explained by the difference between statutory income tax rates in foreign jurisdictions and the domestic federal statutory income tax rate recorded during the period.

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The sum of the differences between the effective income tax rate and domestic federal statutory income tax rate attributable to all nondeductible expenses under enacted tax laws.

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The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate attributable to all other items not otherwise listed in the existing taxonomy.

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The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate that can be explained by research tax credits generated or utilized under enacted tax laws during the period.

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The sum of domestic, foreign and state and local operating loss carryforwards, before tax effects, available to reduce future taxable income under enacted tax laws.

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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
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-Paragraph 48
-Subparagraph a

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