Pension and Severance Plans (Details 4) (JPY ¥) In Millions, unless otherwise specified	12 Months Ended
Mar. 31, 2011	Mar. 31, 2010	Mar. 31, 2009
Japanese Plans [Member]
Projected benefit obligations, the accumulated benefit obligations and fair value of plan assets for pension plans with accumulated benefit obligations in excess of plan assets
Projected benefit obligations	¥ 735,853	¥ 709,554
Accumulated benefit obligations	731,666	705,537
Fair value of plan assets	536,648	515,701
Weighted-average assumptions used to determine benefit obligation
Discount rate	2.10%	2.30%
Rate of compensation increase	0.00%	0.00%
Weighted-average assumptions used to determine net periodic benefit costs
Discount rate	2.30%	2.20%	2.30%
Expected return on plan assets	2.90%	3.60%	3.90%
Rate of compensation increase	0.00%	2.70%	2.50%
Foreign Plans [Member]
Projected benefit obligations, the accumulated benefit obligations and fair value of plan assets for pension plans with accumulated benefit obligations in excess of plan assets
Projected benefit obligations	176,755	177,131
Accumulated benefit obligations	167,609	163,120
Fair value of plan assets	¥ 121,338	¥ 100,526
Weighted-average assumptions used to determine benefit obligation
Discount rate	5.20%	5.50%
Rate of compensation increase	3.50%	4.00%
Weighted-average assumptions used to determine net periodic benefit costs
Discount rate	5.50%	6.50%	6.00%
Expected return on plan assets	5.90%	6.50%	7.10%
Rate of compensation increase	4.00%	3.20%	3.40%

The interest rate used to adjust for the time value of money for the plan.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
-Paragraph 5
-Subparagraph j

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- Definition

Expected rate of compensation increases (for pay-related plans).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
-Paragraph 5
-Subparagraph j

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- Definition

The interest rate used to adjust for the time value of money.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
-Paragraph 5
-Subparagraph j

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- Definition

An assumption as to the rate of return on plan assets reflecting the average rate of earnings expected on the funds invested or to be invested to provide for the benefits included in the benefit obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 87
-Paragraph 264

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
-Paragraph 5
-Subparagraph j

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- Definition

Expected rate of compensation increases (for pay-related plans).

+ References

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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
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-Subparagraph j

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- Definition

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.

+ References

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

If aggregate disclosures are presented, the aggregate projected 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.

+ References

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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
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