Disclosure regarding factors used to determine that the impairment of securities not categorized as either held-to-maturity securities or trading securities (hence equal to available for sale securities) where cost exceeds fair value is not an other than temporary impairment. This item contains disclosure of duration (month) of the temporary impairment of the available-for-sale investments.

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Disclosure regarding factors used to determine that the impairment of securities not categorized as either held-to-maturity securities or trading securities (hence equal to available for sale securities) where cost exceeds fair value is not an other than temporary impairment (OTTI). This item contains disclosure of the number of investment positions in the available-for-sale investments of financial institutions determined to be temporarily impaired.

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Available For Sale Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Positions Others

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Disclosure regarding factors used to determine that the impairment of securities not categorized as either held-to-maturity securities or trading securities (hence equal to available for sale securities) where cost exceeds fair value is not an other than temporary impairment. This item contains disclosure of the severity (percentage of decline) of the temporary impairment of the available-for-sale investments.

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Carrying Amount Of Common Shares

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Fair Value Of Common Shares

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The net gain realized from nonmonetary exchange of cost-method investments. When the cost-method investee is the acquired entity in a business combination, an investor (the reporting entity) exchanges its shares for the acquiring entity and records the exchange at the fair value of the shares received and recognizes a gain determined as the difference between the fair value of the stock received and the investor's cost basis in the shares in the acquired entity.

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This item represents the excess of [amortized] cost over fair value of securities that have been in a loss position for twelve months or longer for those securities which are categorized neither as held-to-maturity nor trading securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Emerging Issues Task Force (EITF)
-Number 03-1
-Paragraph 21
-Subparagraph a(2)

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Staff Position (FSP)
-Number FAS115-1/124-1
-Paragraph 17
-Subparagraph a(1)

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This item represents the excess of [amortized] cost over fair value of securities that have been in a loss position for less than twelve months for those securities which are categorized neither as held-to-maturity nor trading securities.

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This item represents the fair value of securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for less than twelve months.

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This item represents the fair value of securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for twelve months or longer.

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The ratio applied to the debt for purposes of determining the number of shares of the equity security into which the debt will be converted.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 129
-Paragraph 4

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 22
-Article 5

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This element represents the amount by which the carrying amount exceeds the fair value of the investment. The amount is charged to income if the decline in fair value is deemed to be other than temporary.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 16

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Other Investments (Schedule of Gross Unrealized Losses on, and Related Fair Value of Available-For-Sale Securities) (Details) (JPY ¥) In Millions, unless otherwise specified	12 Months Ended
	Mar. 31, 2011	Mar. 31, 2010	Mar. 31, 2009
Fair Value	¥ 9,908	¥ 722
Fair Value
Gross Unrealized Holding Losses	1,131	52
Gross Unrealized Holding Losses
The securities in a continuous unrealized loss position, financial institutions	11
The securities in a continuous unrealized loss position, others	10
The duration of loss position (months)	1
The severity of decline	12.50%
Valuation losses on other investments recognized to reflect the decline in fair value	1,758	143	8,618
Conversion ratio of common shares		0.191
Gain on nonmonetary exchange of securities	2,774
Equity Securities [Member]
Fair Value	9,283	22
Fair Value
Gross Unrealized Holding Losses	1,089	11
Gross Unrealized Holding Losses
Other Equity Securities [Member]
Fair Value	625	700
Fair Value
Gross Unrealized Holding Losses	42	41
Gross Unrealized Holding Losses
MS&AD Insurance Group Holdings, Inc. [Member]
Fair value of common shares	4,140
Nissay Dowa General Insurance Company Limited [Member]
Carrying amount of common shares	¥ 1,366