Contingencies	12 Months Ended
Mar. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Litigation On July 1, 2014, a 100-pound propane cylinder exploded while in use on a food truck in Philadelphia, Pennsylvania. The explosion killed two people and injured eleven. Following the incident, the injured parties and their estates filed a number of lawsuits in the Philadelphia Court of Common Pleas against U-Haul and its subsidiary, U-Haul Co. of Pennsylvania (“UHPA”), alleging that UHPA improperly filled propane cylinders that were overdue for periodic requalification and offered such cylinders for transportation, which allegedly caused the deaths and injuries. One plaintiff also sued AMERCO. All U-Haul defendants denied the allegations. The parties reached agreements to settle the civil cases by April 2018. We have paid a total of $27.9 million, representing our self-insured retention and attorney’s fees for all related civil matters. In June 2018, following the resolution of the civil claims, the United States Attorney's Office for the Eastern District of Pennsylvania filed an initial 6-count indictment and a superseding 7-count indictment against UHPA. In January 2019, the U.S. Attorney's Office agreed to dismiss Counts 1 through 5 alleging UHPA improperly filled propane cylinders that were overdue for periodic requalification and offering such cylinders for transportation. UHPA entered a guilty plea with respect to Counts 6 and 7 relating to a failure to properly train UHPA employees dispensing propane and documentation thereof. On May 7, 2019, the United States District Court for the Eastern District of Pennsylvania accepted the plea agreement and imposed a $1 million fine and two years of probation on UHPA. UHPA was also ordered to pay $800 in associated court fees. Environmental Compliance with environmental requirements of federal, state and local governments may significantly affect Real Estate’s business operations. Among other things, these requirements regulate the discharge of materials into the air, land and water and govern the use and disposal of hazardous substances. Real Estate is aware of issues regarding hazardous substances on some of its properties. Real Estate regularly makes capital and operating expenditures to stay in compliance with environmental laws and has put in place a remedial plan at each site where it believes such a plan is necessary. Since 1988, Real Estate has managed a testing and removal program for underground storage tanks. Based upon the information currently available to Real Estate, compliance with the environmental laws and its share of the costs of investigation and cleanup of known hazardous waste sites are not expected to result in a material adverse effect on AMERCO’s financial position or results of operations. Other We are named as a defendant in various other litigation and claims arising out of the normal course of business. In management’s opinion, none of these other matters will have a material effect on our financial position and results of operations.

Litigation

On July 1, 2014, a 100-pound propane cylinder exploded while in use on a food truck in Philadelphia, Pennsylvania. The explosion killed two people and injured eleven. Following the incident, the injured parties and their estates filed a number of lawsuits in the Philadelphia Court of Common Pleas against U-Haul and its subsidiary, U-Haul Co. of Pennsylvania (“UHPA”), alleging that UHPA improperly filled propane cylinders that were overdue for periodic requalification and offered such cylinders for transportation, which allegedly caused the deaths and injuries. One plaintiff also sued AMERCO. All U-Haul defendants denied the allegations. The parties reached agreements to settle the civil cases by April 2018. We have paid a total of $27.9 million, representing our self-insured retention and attorney’s fees for all related civil matters.

In June 2018, following the resolution of the civil claims, the United States Attorney's Office for the Eastern District of Pennsylvania filed an initial 6-count indictment and a superseding 7-count indictment against UHPA. In January 2019, the U.S. Attorney's Office agreed to dismiss Counts 1 through 5 alleging UHPA improperly filled propane cylinders that were overdue for periodic requalification and offering such cylinders for transportation. UHPA entered a guilty plea with respect to Counts 6 and 7 relating to a failure to properly train UHPA employees dispensing propane and documentation thereof. On May 7, 2019, the United States District Court for the Eastern District of Pennsylvania accepted the plea agreement and imposed a $1 million fine and two years of probation on UHPA. UHPA was also ordered to pay $800 in associated court fees.

Environmental

Compliance with environmental requirements of federal, state and local governments may significantly affect Real Estate’s business operations. Among other things, these requirements regulate the discharge of materials into the air, land and water and govern the use and disposal of hazardous substances. Real Estate is aware of issues regarding hazardous substances on some of its properties. Real Estate regularly makes capital and operating expenditures to stay in compliance with environmental laws and has put in place a remedial plan at each site where it believes such a plan is necessary. Since 1988, Real Estate has managed a testing and removal program for underground storage tanks.

Based upon the information currently available to Real Estate, compliance with the environmental laws and its share of the costs of investigation and cleanup of known hazardous waste sites are not expected to result in a material adverse effect on AMERCO’s financial position or results of operations.

Other

We are named as a defendant in various other litigation and claims arising out of the normal course of business. In management’s opinion, none of these other matters will have a material effect on our financial position and results of operations.