Fair Value of Pension Plan Assets by Asset Category (Parenthetical) (Detail) In Millions, unless otherwise specified						12 Months Ended
Mar. 31, 2011 USD ($)	Mar. 31, 2011 JPY (¥)	Mar. 31, 2010 USD ($)	Mar. 31, 2010 JPY (¥)	Mar. 31, 2009 JPY (¥)	Mar. 31, 2011 ORIX JREIT Inc. Japanese Companies Equity Securities USD ($)	Mar. 31, 2011 ORIX JREIT Inc. Japanese Companies Equity Securities JPY (¥)	Mar. 31, 2010 ORIX JREIT Inc. Japanese Companies Equity Securities JPY (¥)	Mar. 31, 2011 Japanese Government Bond Securities	Mar. 31, 2011 Japanese Municipal Bonds Securities	Mar. 31, 2011 Japanese Corporate Bonds Securities
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]
Fair value of pension plan assets	$ 1,027	¥ 85,396	$ 1,033	¥ 85,967	¥ 74,111	$ 0	¥ 34	¥ 36
Pension plan assets investment allocation in pooled funds									70.00%	10.00%	20.00%

Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items]

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- Definition

Assets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those nonbenefit obligations may be considered as reductions of plan assets.

+ References

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

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

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 87
-Paragraph 49

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- Definition

Target allocation percentage of investments in debt securities to total plan assets presented on a weighted-average basis as of the measurement date of the latest statement of financial position.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
-Paragraph 5
-Subparagraph d(2)

+ Details

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