Consolidating Financial Information by Industry Segment	6 Months Ended
Sep. 30, 2021
Segment Reporting [Abstract]
11. Consolidating Financial Information by Industry Segment	11. Consolidating Financial Information by Industry Segment: AMERCO’s three reportable segments are: Moving and Storage, comprised of AMERCO, U-Haul, and Real Estate and the subsidiaries of UHaul and Real Estate, Property and Casualty Insurance, comprised of Repwest and its subsidiaries and ARCOA, and Life Insurance, comprised of Oxford and its subsidiaries. Management tracks revenues separately, but does not report any separate measure of the profitability for rental vehicles, rentals of self-storage spaces and sales of products that are required to be classified as a separate operating segment and accordingly does not present these as separate reportable segments. Deferred income taxes are shown as liabilities on the condensed consolidating statements. The information includes elimination entries necessary to consolidate AMERCO, the parent, with its subsidiaries. Investments in subsidiaries are accounted for by the parent using the equity method of accounting.

Tabular disclosure of the profit or loss and total assets for each reportable segment. An entity discloses certain information on each reportable segment if the amounts (a) are included in the measure of segment profit or loss reviewed by the chief operating decision maker or (b) are otherwise regularly provided to the chief operating decision maker, even if not included in that measure of segment profit or loss.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 25
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8813-108599

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8906-108599

Name:	us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration