XML 61 R34.htm IDEA: XBRL DOCUMENT v2.4.1.9
Marketable Securities (Details) (USD $)
In Thousands, unless otherwise specified
Apr. 30, 2015
Jul. 31, 2014
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost $ 31,372us-gaap_AvailableForSaleSecuritiesAmortizedCost $ 12,881us-gaap_AvailableForSaleSecuritiesAmortizedCost
Gross Unrealized Gains 7idt_AvailableForSaleDebtSecuritiesGrossUnrealizedGains 1idt_AvailableForSaleDebtSecuritiesGrossUnrealizedGains
Gross Unrealized Losses (3)idt_AvailableForSaleDebtSecuritiesGrossUnrealizedLosses (9)idt_AvailableForSaleDebtSecuritiesGrossUnrealizedLosses
Fair Value 31,376us-gaap_MarketableSecuritiesCurrent 12,873us-gaap_MarketableSecuritiesCurrent
Certificates of Deposit [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 19,290us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CertificatesOfDepositMember
[1] 10,375us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CertificatesOfDepositMember
[1]
Gross Unrealized Gains 1idt_AvailableForSaleDebtSecuritiesGrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CertificatesOfDepositMember
[1]    [1]
Gross Unrealized Losses    [1]    [1]
Fair Value 19,291us-gaap_MarketableSecuritiesCurrent
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CertificatesOfDepositMember
[1] 10,375us-gaap_MarketableSecuritiesCurrent
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CertificatesOfDepositMember
[1]
Federal Home Loan Bank bond [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 995us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_FederalHomeLoanBankBorrowingsMember
 
Gross Unrealized Gains     
Gross Unrealized Losses     
Fair Value 995us-gaap_MarketableSecuritiesCurrent
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_FederalHomeLoanBankBorrowingsMember
 
International agency notes [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 1,120us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= exch_XIMM
 
Gross Unrealized Gains 2idt_AvailableForSaleDebtSecuritiesGrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= exch_XIMM
 
Gross Unrealized Losses     
Fair Value 1,122us-gaap_MarketableSecuritiesCurrent
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= exch_XIMM
 
Equity Securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost   31us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_EquitySecuritiesMember
Gross Unrealized Gains     
Gross Unrealized Losses   (9)idt_AvailableForSaleDebtSecuritiesGrossUnrealizedLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_EquitySecuritiesMember
Fair Value   22us-gaap_MarketableSecuritiesCurrent
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_EquitySecuritiesMember
Municipal Bonds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 9,967us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
2,475us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Gross Unrealized Gains 4idt_AvailableForSaleDebtSecuritiesGrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
1idt_AvailableForSaleDebtSecuritiesGrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Gross Unrealized Losses (3)idt_AvailableForSaleDebtSecuritiesGrossUnrealizedLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
  
Fair Value $ 9,968us-gaap_MarketableSecuritiesCurrent
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
$ 2,476us-gaap_MarketableSecuritiesCurrent
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
[1] Each of the Company's certificates of deposit has a CUSIP, was purchased in the secondary market through a broker and may be sold in the secondary market.