Quantitative Information About Delinquencies, Net Credit Losses, and Components of Financial Assets Sold on Securitization and Other Assets Managed Together (Detail) In Millions	12 Months Ended
Mar. 31, 2011 USD ($)	Mar. 31, 2011 JPY (¥)	Mar. 31, 2010 JPY (¥)	Mar. 31, 2011 Direct financing leases USD ($)	Mar. 31, 2011 Direct financing leases JPY (¥)	Mar. 31, 2010 Direct financing leases JPY (¥)	Mar. 31, 2011 Installment Loans JPY (¥)	Mar. 31, 2011 Installment Loans USD ($)	Mar. 31, 2010 Installment Loans JPY (¥)
Assets that Continue to be Recognized, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together [Line Items]
Principal amount of Assets managed or sold on securitization receivables	$ 45,911	¥ 3,817,510	¥ 3,459,020	$ 10,034	¥ 834,346	¥ 883,452	¥ 2,983,164	$ 35,877	¥ 2,575,568
Less: assets sold on securitization	(42)	(3,493)	(238,288)
Assets held in portfolio	45,869	3,814,017	3,220,732
Principal amount of assets managed or sold on securitization receivables more than 90 days past-due and impaired loans	4,147	344,855	386,146	274	22,787	25,682	322,068	3,873	360,464
Assets managed or sold on securitization net credit losses	$ 741	¥ 61,654	¥ 57,797	$ 90	¥ 7,505	¥ 8,744	¥ 54,149	$ 651	¥ 49,053

This is the principal amount outstanding for securitized Financial Assets only.

Name:	ix_PrincipalAmountOutstandingOnFinancialAssetsSecuritized
Namespace Prefix:	ix
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

This is the principal amount of loans (across all types of loans) that are overdue in payment by a set number of days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Staff Position (FSP)
-Number FAS140-4 and FIN46(R)-8
-Paragraph B11
-Subparagraph b(6)

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 140
-Paragraph 17
-Subparagraph i(4)

+ Details

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

- Definition

This is the sum of charge-offs (credit losses) on loans managed or securitized during the period.

+ References

+ Details

Name:	us-gaap_NetCreditLossesDuringPeriodOnLoansManagedOrSecuritized
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This is the result of the principal amount outstanding of total loans managed or securitized less securitized loans and loans that are in the process of being securitized.

+ References

+ Details

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

- Definition

This is the sum of principal amount outstanding for both securitized and unsecuritized loans of all types.

+ References

+ Details

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

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration