Retirement and Severance Benefits (Schedule of Projected Benefit Obligations (Details) (JPY ¥) In Millions	Mar. 31, 2011	Mar. 31, 2010
Retirement and Severance Benefits
Projected benefit obligations	¥ 2,135,047	¥ 2,094,302
Fair value of plan assets	1,635,656	1,649,951
Accumulated benefit obligations	2,078,759	2,035,647
Fair value of plan assets	¥ 1,632,963	¥ 1,649,951

If aggregate disclosures are presented, the aggregate pension accumulated benefit obligation for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
-Paragraph 6
-Subparagraph b

+ Details

Name:	us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

If aggregate disclosures are presented, the aggregate fair value of plan assets for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
-Paragraph 6
-Subparagraph b

+ Details

Name:	us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

If aggregate disclosures are presented, the aggregate benefit obligation for plans with benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
-Paragraph 6
-Subparagraph a

+ Details

Name:	us-gaap_DefinedBenefitPlanPlansWithBenefitObligationsInExcessOfPlanAssetsAggregateBenefitObligation
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

If aggregate disclosures are presented, the aggregate fair value of plan assets for plans with benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
-Paragraph 6
-Subparagraph a

+ Details

Name:	us-gaap_DefinedBenefitPlanPlansWithBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_GeneralDiscussionOfPensionAndOtherPostretirementBenefitsAbstract
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration