XML 44 R33.htm IDEA: XBRL DOCUMENT
v3.8.0.1

IDT Financial Services Holding Limited Assets and Liabilities Held for Sale (Details Textual) - USD ($) $ in Thousands | 6 Months Ended |
--- | --- | ---
Jan. 31, 2018 | Jul. 31, 2017
IDT Financial Services Holding Limited Assets and Liabilities Held for Sale (Textual) |  |
Allowance for doubtful accounts | $ 3,239 | $ 2,550
Net asset value | 14,500 |
IDT Financial Services Holding Limited [Member] |  |
IDT Financial Services Holding Limited Assets and Liabilities Held for Sale (Textual) |  |
Outstanding equity interests | $ 4,100 |

X
- References No definition available. + Details
Name: | idt_AssetsAndLiabilitiesHeldForSaleTextualAbstract
Namespace Prefix: | idt_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount classified as allowance for doubtful accounts attributable to disposal group held for sale or disposed of. + References No definition available. + Details
Name: | idt_DisposalGroupIncludingDiscontinuedOperationAllowanceForDoubtfulAccounts
Namespace Prefix: | idt_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of net assets (liabilities). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 225 -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(6)) -URI http://asc.fasb.org/extlink&oid=6488393&loc=d3e606914-122999 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 210 -Section S99 -Paragraph 2 -Subparagraph (SX 210.6-05(4)) -URI http://asc.fasb.org/extlink&oid=6488278&loc=d3e604008-122996 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 205 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=79984436&loc=d3e9915-115836 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 30 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=77885760&loc=SL35686385-199418 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 225 -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(7)) -URI http://asc.fasb.org/extlink&oid=6488393&loc=d3e606914-122999 + Details
Name: | us-gaap_AssetsNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The cash inflow associated with the deconsolidation of a previously consolidated subsidiary or the sale of investment in consolidated subsidiaries (generally greater than 50 percent). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 12 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3179-108585 + Details
Name: | us-gaap_ProceedsFromDivestitureOfInterestInConsolidatedSubsidiaries
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | dei_LegalEntityAxis=idt_IdtFinancialServicesHoldingLimitedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |