The amount of collaborative agreement purchase price.

No definition available.

Name:	immu_CollaborativeArrangementPurchasePrice
Namespace Prefix:	immu_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents gross proceeds from issuance of common stock before deducting underwriting discounts and commissions and estimated expense.

+ References

No definition available.

+ Details

Name:	immu_GrossProceedsFromIssuanceOfCommonStock
Namespace Prefix:	immu_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of increase in cash due to collaborative agreements.

+ References

No definition available.

+ Details

Name:	immu_IncreaseInCashDueToCollaborativeAgreements
Namespace Prefix:	immu_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number Of Subsidiaries

+ References

No definition available.

+ Details

Name:	immu_NumberOfSubsidiaries
Namespace Prefix:	immu_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the minimum number therapies received of necessary for patients with metastatic triple-negative breast cancer "("mTNBC") in order to determine if a patient is eligible for IMMU-132.

+ References

No definition available.

+ Details

Name:	immu_NumberOfTherapiesReceived
Namespace Prefix:	immu_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of trailing days.

+ References

No definition available.

+ Details

Name:	immu_NumberOfTrailingDays
Namespace Prefix:	immu_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represent premium over the stocks.

+ References

No definition available.

+ Details

Name:	immu_PercentageOfPremiumOverSharePrice
Namespace Prefix:	immu_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Cash includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the customer may deposit additional funds at any time and effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid Investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Short-term investments, exclusive of cash equivalents, generally consist of marketable securities intended to be sold within one year (or the normal operating cycle if longer) and may include trading securities, available-for-sale securities, or held-to-maturity securities (if maturing within one year), as applicable.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.1)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

Price of a single share of a number of saleable stocks of a company.

+ References

No definition available.

+ Details

Name:	us-gaap_SharePrice
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_CounterpartyNameAxis=immu_RpiFinanceTrustMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=immu_FundingAndPurchaseAgreementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=us-gaap_PrivatePlacementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=immu_CommonStockPurchaseAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Business Overview and Basis of Presentation (Details) $ / shares in Units, $ in Millions				9 Months Ended
	Jan. 08, 2018 USD ($) $ / shares	Jan. 07, 2018 USD ($) $ / shares	Oct. 11, 2016 USD ($)	Mar. 31, 2018 USD ($) item subsidiary
Minimum number therapies received \| item				2
Number of subsidiaries \| subsidiary				2
Cash, cash equivalents and marketable securities				$ 358.8
Gross proceeds from sale of common stock			$ 30.0
RPI
Number of trailing days	15 days
Increase in cash due to collaborative agreements	$ 250.0
RPI \| Minimum
Premium over the stock’s	15.00%
Funding and Purchase Agreements [Member] \| RPI
Collaborative agreement purchase price	$ 175.0	$ 175.0
Private placement \| Common stock purchase agreement \| RPI
Gross proceeds from sale of common stock	$ 75.0	$ 75.0
Share Price \| $ / shares	$ 17.15	$ 17.15