CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
Apr. 30, 2011	Apr. 30, 2010	Apr. 30, 2009
REVENUE
Real estate rentals	$ 192,178	$ 186,321	$ 183,153
Tenant reimbursement	45,007	44,994	45,167
TOTAL REVENUE	237,185	231,315	228,320
EXPENSES
Depreciation/amortization related to real estate investments	55,809	55,054	52,335
Utilities	18,238	17,101	18,112
Maintenance	29,240	26,972	26,431
Real estate taxes	30,852	30,210	29,077
Insurance	2,304	3,615	2,864
Property management expenses	21,276	18,380	16,716
Administrative expenses	6,617	5,716	4,430
Advisory and trustee services	605	502	452
Other expenses	1,774	2,513	1,440
Amortization related to non-real estate investments	2,679	2,362	2,060
Impairment of real estate investments	0	708	0
TOTAL EXPENSES	169,394	163,133	153,917
Gain on involuntary conversion	0	1,660	0
Interest expense	(63,941)	(65,581)	(64,928)
Interest income	259	539	599
Other income	282	355	314
Income from continuing operations	4,391	5,155	10,388
Income (loss) from discontinued operations	19,960	(570)	325
NET INCOME	24,351	4,585	10,713
Net income attributable to noncontrolling interests - Operating Partnership	(4,449)	(562)	(2,227)
Net loss (income) attributable to noncontrolling interests - consolidated real estate entities	180	(22)	40
Net income attributable to Investors Real Estate Trust	20,082	4,001	8,526
Dividends to preferred shareholders	(2,372)	(2,372)	(2,372)
NET INCOME AVAILABLE TO COMMON SHAREHOLDERS	$ 17,710	$ 1,629	$ 6,154
Earnings per common share from continuing operations - Investors Real Estate Trust - basic and diluted	$ 0.0200	$ 0.0400	$ 0.1000
Earnings (loss) per common share from discontinued operations - Investors Real Estate Trust - basic and diluted	$ 0.2000	$ (0.0100)	$ 0.0100
NET INCOME PER COMMON SHARE - BASIC & DILUTED	$ 0.2200	$ 0.0300	$ 0.1100
DIVIDENDS PER COMMON SHARE	$ 0.6860	$ 0.6845	$ 0.6770

Impairment of real estate investments with different values from Cash Flows element.

No definition available.

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Balance Type:	credit
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- Definition

The amount of net income or loss for the period per each share of common stock outstanding during the reporting period. And the amount of net income or loss for the period per each share of common stock and dilutive common stock equivalents outstanding during the reporting period.

+ References

No definition available.

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Namespace Prefix:	iret_
Data Type:	us-types:perShareItemType
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- Definition

Costs incurred to provide to tenants basic services such as electricity, gas, water, telephone, cable, and internet service.

+ References

No definition available.

+ Details

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Namespace Prefix:	iret_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

This element represents the amortization of deferred leasing fees incurred by the lessor and amortized over the term of the lease. Such fees represent (a) costs to originate a lease incurred in transactions with independent third parties that (i) result directly from and are essential to acquire that lease and (ii) would not have been incurred had that leasing transaction not occurred and (b) certain costs directly related to specified activities performed by the lessor for that lease. Those activities are: evaluating the prospective lessee's financial condition; evaluating and recording guarantees, collateral, and other security arrangements; negotiating lease terms; preparing and processing lease documents; and closing the transaction.

+ References

No definition available.

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- Definition

Aggregate dividends declared during the period for each share of common stock outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

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- Definition

The aggregate costs of keeping the property in good condition but that do not appreciably prolong the life or increase the value of the property.

+ References

No definition available.

+ Details

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- Definition

Total costs of sales and operating expenses for the period.

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No definition available.

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- Definition

The current period expense charged against earnings on long-lived, physical assets not used in production, and which are not intended for resale, to allocate or recognize the cost of such assets over their useful lives; or to record the reduction in book value of an intangible asset over the benefit period of such asset; or to reflect consumption during the period of an asset that is not used in production.

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 28

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-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 12

-Paragraph 5

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- Definition

The net amount (to the extent disclosed within this portion of the income statement) by which an insurance settlement exceeds incremental costs incurred from the event causing an interruption of business, plus the insurance award for earnings lost from the event, such as a natural catastrophe, explosion or fire.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Emerging Issues Task Force (EITF)

-Number 01-13

-Paragraph 7

-Subparagraph b

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- Definition

The aggregate total of expenses of managing and administering the affairs of an entity, including affiliates of the reporting entity, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

+ References

No definition available.

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- Definition

This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses and taxes from ongoing operations before extraordinary items, cumulative effects of changes in accounting principles, and noncontrolling interest.

+ References

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The amount of income (loss) from continuing operations per each share of common stock outstanding during the reporting period.

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-Publisher SEC

-Name Regulation S-X (SX)

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-Number 210

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- Definition

This element represents the overall income (loss) from a disposal group that is classified as a component of the entity, net of income tax, reported as a separate component of income before extraordinary items and the cumulative effect of accounting changes before deduction or consideration of the amount which may be allocable to noncontrolling interests, if any. Includes the following (net of tax): income (loss) from operations during the phase-out period, gain (loss) on disposal, provision (or any reversals of earlier provisions) for loss on disposal, and adjustments of a prior period gain (loss) on disposal.

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-Publisher SEC

-Name Regulation S-X (SX)

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-Section 04

-Paragraph 13

-Article 7

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

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-Paragraph 15

-Article 5

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-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 29

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-Number 144

-Paragraph 43

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 144

-Paragraph 47

-Subparagraph c

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The amount of income (loss) from disposition of discontinued operations, net of related tax effect, per each share of common stock outstanding during the reporting period.

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 128

-Paragraph 8, 9, 10, 36, 37, 38

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-Number 210

-Section 04

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- Definition

The cost of borrowed funds accounted for as interest that was charged against earnings during the period.

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 34

-Paragraph 21

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-Publisher OTS

-Name Federal Regulation (FR)

-Number Title 12

-Chapter V

-Section 563c.102

-Paragraph 9

-Subsection II

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 9

-Article 9

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Income derived from investments in debt securities and on cash and cash equivalents the earnings of which reflect the time value of money or transactions in which the payments are for the use or forbearance of money.

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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 14

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Article 5

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of net income (loss) for the period allocated to noncontrolling partners in an operating partnership included in the entity's consolidated financial statements.

+ References

+ Details

Name:	us-gaap_MinorityInterestInNetIncomeLossOperatingPartnerships
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The portion of consolidated profit or loss for the period, net of income taxes, which is attributable to the parent. If the entity does not present consolidated financial statements, the amount of profit or loss for the period, net of income taxes.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 19

-Article 5

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-Publisher AICPA

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-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph A7

-Appendix A

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 130

-Paragraph 10, 15

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-Publisher FASB

-Name Emerging Issues Task Force (EITF)

-Number 87-21

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 28, 29, 30

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- Definition

The portion of net income (loss) attributable to the noncontrolling interest (if any) deducted in order to derive the portion attributable to the parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 38

-Subparagraph a

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-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 38

-Subparagraph c(1)

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-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph A1, A4, A5

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- Definition

Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 128

-Paragraph 9

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Name:	us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The total amount of revenue recognized for the period from operating leases, including minimum lease revenue, contingent revenue, percentage revenue and sublease revenue.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 13

-Paragraph 19

-Subparagraph b

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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- Definition

Amount of general expenses not normally included in Other Operating Costs and Expenses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 6

-Article 5

+ Details

Name:	us-gaap_OtherGeneralExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The net amount of other nonoperating income and expense, which does not qualify for separate disclosure on the income statement under materiality guidelines.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 9

-Article 5

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The aggregate costs related to management of owned properties during the reporting period.

+ References

No definition available.

+ Details

Name:	us-gaap_OwnedPropertyManagementCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of dividends declared or paid in the period to preferred shareholders, or the amount for which the obligation to pay them dividends arose in the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 6

-Section B

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-Name Accounting Principles Board Opinion (APB)

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-Number 210

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-Name Statement of Financial Accounting Standard (FAS)

-Number 128

-Paragraph 40

-Subparagraph b

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- Definition

The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

+ References

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-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

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-Paragraph A1, A4, A5

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-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 38

-Subparagraph c(1)

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Balance Type:	credit
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- Definition

A contract to provide coverage or protection in exchange for a payment or "premium". Examples of insurance protection include liability and property insurance. The entity paying the premiums for the protection will have insurance expense and possibly an asset, Prepaid Insurance (if the premiums are paid in advance).

+ References

No definition available.

+ Details

Name:	us-gaap_RealEstateInsurance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The aggregate revenue from real estate operations during the reporting period.

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

+ Details

Name:	us-gaap_RealEstateRevenueNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

A tax based on the assessed value of real estate by the local government. The tax is usually based on the value of property (including the land).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 43

-Chapter 10

-Section A

-Paragraph 2, 17

+ Details

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Balance Type:	debit
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- Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
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- Definition

In accordance with the provisions of their lease agreement, this element represents allowable charges due a landlord from its tenant. In retail store and office building leases, for example, tenant reimbursements may cover items such as taxes, utilities, and common area expenses.

+ References

No definition available.

+ Details

Name:	us-gaap_TenantReimbursements
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Balance Type:	credit
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- Definition

Fees charged annually for the professional services of a trustee, usually quoted as a percentage of the funds being managed. An offshore trust must have a Trustee who will administer the assets in the trust for the Beneficiaries. The fee for appointing an offshore Trustee is included in the trust price.

+ References

No definition available.

+ Details

Name:	us-gaap_TrusteeFees
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Balance Type:	debit
Period Type:	duration