Basis Points Spread

No definition available.

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- Definition

Line of Credit Covenant Maximum Amount of Loans and Advances to Affiliates or Subsidiaries

+ References

No definition available.

+ Details

Name:	idt_LineOfCreditCovenantMaximumAmountOfLoansAndAdvancesToAffiliatesOrSubsidiaries
Namespace Prefix:	idt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

+ Details

Name:	idt_RevolvingCreditLoanPayableTextualAbstract
Namespace Prefix:	idt_
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Balance Type:	na
Period Type:	duration

- Definition

Date the credit facility terminates, in CCYY-MM-DD format.

+ 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 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Description of the interest rate for the amounts borrowed under the credit facility, including the terms and the method for determining the interest rate (for example, fixed or variable, LIBOR plus a percentage, increasing rate, timing of interest rate resets, remarketing provisions).

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityInterestRateDescription
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Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of borrowings from a bank classified as other, maturing within one year or operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.16)
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(a)(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:	credit
Period Type:	instant

- Details

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- Details

Name:	us-gaap_LineOfCreditFacilityAxis=idt_JulyTwelveTwoThousandTwelveMember
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Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=us-gaap_PrimeRateMember
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Revolving Credit Loan Payable (Details) $ in Millions		3 Months Ended
Revolving Credit Loan Payable (Details) $ in Millions	Jul. 12, 2012 USD ($) BasisPoint	Oct. 31, 2017 USD ($)	Jul. 31, 2017 USD ($)
Revolving Credit Loan Payable (Textual)
Maximum principal amount of credit agreement	$ 25.0
Unused outstanding amount	$ 25.0
Line of credit maturity date		Apr. 30, 2018
Average percentage of commitment fee per annum	0.375%
Maximum amount of investments in and advances to affiliates at fair value	$ 110.0
Line of credit [Member]
Revolving Credit Loan Payable (Textual)
Line of credit facility, outstanding
July 12, 2012 [Member]
Revolving Credit Loan Payable (Textual)
Interest rate description		The principal outstanding bears interest per annum, at the option of IDT Telecom, at either (a) the U.S. Prime Rate less 125 basis points, or (b) the LIBOR rate adjusted by the Regulation D maximum reserve requirement plus 150 basis points.
Prime Rate [Member]
Revolving Credit Loan Payable (Textual)
U.S. Prime rate basis points \| BasisPoint	125