Basis of Presentation	9 Months Ended
Basis of Presentation	Dec. 31, 2012
Disclosure Text Block [Abstract]
1. Basis of Presentation	1. Basis of Presentation AMERCO, a Nevada corporation (“AMERCO”), has a third fiscal quarter that ends on the 31^st of December for each year that is referenced. Our insurance company subsidiaries have a third quarter that ends on the 30^th of September for each year that is referenced. They have been consolidated on that basis. Our insurance companies' financial reporting processes conform to calendar year reporting as required by state insurance departments. Management believes that consolidating their calendar year into our fiscal year financial statements does not materially affect the financial position or results of operations. The Company discloses any material events occurring during the intervening period. Consequently, all references to our insurance subsidiaries' years 2012 and 2011 correspond to fiscal 2013 and 2012 for AMERCO. Accounts denominated in non-U.S. currencies have been translated into U.S. dollars. Certain amounts reported in previous years have been reclassified to conform to the current presentation. The condensed consolidated balance sheet as of December 31, 2012 and the related condensed consolidated statements of operations and comprehensive income for the third quarter and the first nine months and the cash flows for the first nine months ended fiscal 2013 and 2012 are unaudited. In our opinion, all adjustments necessary for the fair presentation of such condensed consolidated financial statements have been included. Such adjustments consist only of normal recurring items. Interim results are not necessarily indicative of results for a full year. The information in this Quarterly Report on Form 10-Q (“Quarterly Report”) should be read in conjunction with Management's Discussion and Analysis of Financial Condition and Results of Operations and financial statements and notes thereto included in our Annual Report on Form 10-K for the fiscal year ended March 31, 2012. Intercompany accounts and transactions have been eliminated. Description of Legal Entities AMERCO is the holding company for: U-Haul International, Inc. (“U-Haul”), Amerco Real Estate Company (“Real Estate”), Repwest Insurance Company (“Repwest”), and Oxford Life Insurance Company (“Oxford”). Unless the context otherwise requires, the term “Company,” “we,” “us” or “our” refers to AMERCO and all of its legal subsidiaries. Description of Operating Segments AMERCO has three reportable segments. They are Moving and Storage, Property and Casualty Insurance and Life Insurance. The Moving and Storage operating segment includes AMERCO, U-Haul, and Real Estate and the wholly-owned subsidiaries of U-Haul and Real Estate. Operations consist of the rental of trucks and trailers, sales of moving supplies, sales of towing accessories, sales of propane, and the rental of fixed and mobile self-storage spaces to the “do-it-yourself” mover and management of self-storage properties owned by others. Operations are conducted under the registered trade name U-Haul^® throughout the United States and Canada. The Property and Casualty Insurance operating segment includes Repwest and its wholly-owned subsidiaries and ARCOA risk retention group (“ARCOA”). The Property and Casualty Insurance operating segment provides loss adjusting and claims handling for U-Haul through regional offices across North America. The Property and Casualty Insurance operating segment also underwrites components of the Safemove, Safetow, Super Safemove and Safestor protection packages to U-Haul customers. The business plan for the Property and Casualty Insurance operating segment includes offering property and casualty products in other U-Haul related programs. ARCOA is a group captive insurer owned by us and our wholly-owned subsidiaries whose purpose is to provide insurance products related to the moving and storage business. The Life Insurance operating segment includes Oxford and its wholly-owned subsidiaries. Oxford provides life and health insurance products primarily to the senior market through the direct writing or reinsuring of life insurance, Medicare supplement and annuity policies.