Commitments and Contingencies	3 Months Ended
Jul. 01, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Warranty The Company maintains an accrual for obligations it incurs under its standard product warranty program and customer, part, or process specific matters. The Company’s standard warranty period is one year, however in certain instances the warranty period may be extended to as long as two years. Management estimates the fair value of the Company’s warranty liability based on actual past warranty claims experience, its policies regarding customer warranty returns and other estimates about the timing and disposition of product returned under the standard program. Customer, part, or process specific accruals are estimated using a specific identification method. Historical profit and loss impact related to warranty returns activity has been minimal. The total warranty accrual was $0.3 million as of both July 1, 2018 and April 1, 2018. Litigation On March 23, 2018, a compliant for patent infringement was served on the Company by DIFF Scale Operations Research, LLC (“DSOR”) in the Federal Court for the District of Delaware. DSOR alleged to be the owner of a certain collection of patents previously owned by ADC Communications, some of which were the subject of the litigation against the Company. This dispute between the parties has now been resolved, and the court case dismissed based on a joint stipulation of the parties on June 28, 2018, with no finding of infringement liability against IDT. In January 2012, Maxim I Properties, a general partnership that had purchased a certain parcel of real property (the Property) in 2003, filed a complaint in the Northern District of California naming approximately 30 defendants, including the Company ("Defendants"), alleging various environmental violations of the federal Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and Resource Conservation and Recovery Act (RCRA), the California Hazardous Substance Account Act (HSAA), and other common law claims (the Complaint). The Complaint alleged that Defendants including the Company “…generated, transported, and/or arranged for the transport and/or disposal of hazardous waste to the Property.” On August 15, 2012, Maxim I Properties voluntarily dismissed its Complaint without prejudice. However, another defendant, Moyer Products, Inc., counter-claimed against the plaintiff, Maxim, and cross-claimed against the remaining co-Defendants, including the Company. Thus, the Company remains a cross-defendant in this action. In a related, but independent action, the California Department of Toxic Substances Control (DTSC) notified the Company in September 2012 that the Company, and more than 50 other entities, were being named as respondents to DTSC's Enforcement Order, as “a generator of hazardous waste.” In April 2013, the Company, along with the other “respondent” parties, entered into a Corrective Action Consent Agreement (CACA) with the DTSC, agreeing to conduct the Property investigation and corrective action selection. The CACA supersedes the DTSC's Enforcement Order. The District Court for the Northern District of California stayed the Maxim/Moyer litigation pending the Property investigation under the CACA and DTSC's corrective action selection. Property investigation activity took place between April 2013 and June 2015. On June 23, 2015, the DTSC deemed the Property investigation complete. The DTSC continues to evaluate corrective action alternatives. The Company will continue to vigorously defend itself against the allegations in the Complaint and evaluate settlement options with Moyer upon notification from DTSC of its corrective action selection. No specific corrective action has been selected yet, and thus no specific monetary demands have been made. The Company may also be a party to various other legal proceedings and claims arising in the normal course of business from time to time. With regard to the matters listed above, along with various other legal proceedings and claims and future matters that may arise, potential liability and probable losses or ranges of possible losses due to an unfavorable litigation outcome cannot be reasonably estimated at this time. Generally, litigation is subject to inherent uncertainties, and no assurance can be given that the Company will prevail in any particular lawsuit or claim. Pending lawsuits, claims as well as potential future litigation, could result in substantial costs and diversion of resources and could have a material adverse effect on the Company's financial condition, results of operations or cash flows.

Commitments and Contingencies

Warranty

The Company maintains an accrual for obligations it incurs under its standard product warranty program and customer, part, or process specific matters. The Company’s standard warranty period is one year, however in certain instances the warranty period may be extended to as long as two years. Management estimates the fair value of the Company’s warranty liability based on actual past warranty claims experience, its policies regarding customer warranty returns and other estimates about the timing and disposition of product returned under the standard program. Customer, part, or process specific accruals are estimated using a specific identification method. Historical profit and loss impact related to warranty returns activity has been minimal. The total warranty accrual was $0.3 million as of both July 1, 2018 and April 1, 2018.

Litigation

On March 23, 2018, a compliant for patent infringement was served on the Company by DIFF Scale Operations Research, LLC (“DSOR”) in the Federal Court for the District of Delaware. DSOR alleged to be the owner of a certain collection of patents previously owned by ADC Communications, some of which were the subject of the litigation against the Company. This dispute between the parties has now been resolved, and the court case dismissed based on a joint stipulation of the parties on June 28, 2018, with no finding of infringement liability against IDT.

In January 2012, Maxim I Properties, a general partnership that had purchased a certain parcel of real property (the Property) in 2003, filed a complaint in the Northern District of California naming approximately 30 defendants, including the Company ("Defendants"), alleging various environmental violations of the federal Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and Resource Conservation and Recovery Act (RCRA), the California Hazardous Substance Account Act (HSAA), and other common law claims (the Complaint). The Complaint alleged that Defendants including the Company “…generated, transported, and/or arranged for the transport and/or disposal of hazardous waste to the Property.” On August 15, 2012, Maxim I Properties voluntarily dismissed its Complaint without prejudice. However, another defendant, Moyer Products, Inc., counter-claimed against the plaintiff, Maxim, and cross-claimed against the remaining co-Defendants, including the Company. Thus, the Company remains a cross-defendant in this action.

In a related, but independent action, the California Department of Toxic Substances Control (DTSC) notified the Company in September 2012 that the Company, and more than 50 other entities, were being named as respondents to DTSC's Enforcement Order, as “a generator of hazardous waste.” In April 2013, the Company, along with the other “respondent” parties, entered into a Corrective Action Consent Agreement (CACA) with the DTSC, agreeing to conduct the Property investigation and corrective action selection. The CACA supersedes the DTSC's Enforcement Order. The District Court for the Northern District of California stayed the Maxim/Moyer litigation pending the Property investigation under the CACA and DTSC's corrective action selection.

Property investigation activity took place between April 2013 and June 2015. On June 23, 2015, the DTSC deemed the Property investigation complete. The DTSC continues to evaluate corrective action alternatives. The Company will continue to vigorously defend itself against the allegations in the Complaint and evaluate settlement options with Moyer upon notification from DTSC of its corrective action selection. No specific corrective action has been selected yet, and thus no specific monetary demands have been made.

The Company may also be a party to various other legal proceedings and claims arising in the normal course of business from time to time. With regard to the matters listed above, along with various other legal proceedings and claims and future matters that may arise, potential liability and probable losses or ranges of possible losses due to an unfavorable litigation outcome cannot be reasonably estimated at this time. Generally, litigation is subject to inherent uncertainties, and no assurance can be given that the Company will prevail in any particular lawsuit or claim. Pending lawsuits, claims as well as potential future litigation, could result in substantial costs and diversion of resources and could have a material adverse effect on the Company's financial condition, results of operations or cash flows.