Consolidating Financial Information By Industry Segment (Table Text Block)	3 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Table Text Block Supplement [Abstract]
Consolidated Balance Sheet by Industry Segment	Consolidating balance sheets by industry segment as of June 30, 2023 are as follows:       Moving & Storage Consolidated   Property & Casualty Insurance (a)   Life Insurance (a)   Eliminations     U-Haul Holding Company Consolidated     (Unaudited)     (In thousands) Assets:   Cash and cash equivalents $ 2,302,380 $ 14,038 $ 60,706 $ –   $ 2,377,124 Reinsurance recoverables and trade receivables, net   125,222   49,051   32,390   –     206,663 Inventories and parts, net   164,884   –   –   –     164,884 Prepaid expenses   232,039   –   –   –     232,039 Investments, fixed maturities and marketable equities   –   274,003   2,195,509   –     2,469,512 Investments, other   23,330   129,392   467,418   –     620,140 Deferred policy acquisition costs, net   –   –   123,596   –     123,596 Other assets   54,916   1,063   4,842   –     60,821 Right of use assets - financing, net   420,496   –   –   –     420,496 Right of use assets - operating, net   58,622   850   24   –     59,496 Related party assets   65,625   2,860   11,945   (37,328) (c)   43,102     3,447,514   471,257   2,896,430   (37,328)     6,777,873                         Investment in subsidiaries   459,095   –   –   (459,095) (b)   –                         Property, plant and equipment, at cost:                       Land   1,555,326   –   –   –     1,555,326 Buildings and improvements   7,364,517   –   –   –     7,364,517 Furniture and equipment   942,036   –   –   –     942,036 Rental trailers and other rental equipment   866,916   –   –   –     866,916 Rental trucks   5,594,132   –   –   –     5,594,132     16,322,927   –   –   –     16,322,927 Less:   Accumulated depreciation   (4,486,766)   –   –   –     (4,486,766) Total property, plant and equipment, net   11,836,161   –   –   –     11,836,161 Total assets $ 15,742,770 $ 471,257 $ 2,896,430 $ (496,423)   $ 18,614,034                         (a) Balances as of March 31, 2023                       (b) Eliminate investment in subsidiaries                       (c) Eliminate intercompany receivables and payables                       Consolidating balance sheets by industry segment as of June 30, 2023, continued       Moving & Storage   Property & Casualty Insurance (a)   Life   Eliminations     U-Haul Holding Company     (Unaudited)     (In thousands) Liabilities:                       Accounts payable and accrued expenses $ 768,784 $ 3,303 $ 6,518 $ –   $ 778,605 Notes, loans and finance leases payable, net   6,287,231   –   –   –     6,287,231 Operating lease liabilities   57,937   864   7   –     58,808 Policy benefits and losses, claims and loss expenses payable   328,009   148,960   401,467   –     878,436 Liabilities from investment contracts   –   –   2,384,330   –     2,384,330 Other policyholders' funds and liabilities   –   2,435   9,783   –     12,218 Deferred income   64,790   –   –   –     64,790 Deferred income taxes, net   1,437,773   4,776   (70,690)   –     1,371,859 Related party liabilities   26,630   3,199   13,640   (43,469) (c)   – Total liabilities   8,971,154   163,537   2,745,055   (43,469)     11,836,277                         Stockholders' equity:                       Series preferred stock:                       Series A preferred stock   –   –   –   –     – Series B preferred stock   –   –   –   –     – Series A common stock   –   –   –   –     – Voting Common stock   10,497   3,301   2,500   (5,801) (b)   10,497 Non-Voting Common stock   176   –   –   –     176 Additional paid-in capital   453,853   91,120   26,271   (117,601) (b)   453,643 Accumulated other comprehensive income (loss)   (267,977)   (11,043)   (207,495)   224,679 (b)   (261,836) Retained earnings   7,252,717   224,342   330,099   (554,231) (b)   7,252,927 Cost of common stock in treasury, net   (525,653)   –   –   –     (525,653) Cost of preferred stock in treasury, net   (151,997)   –   –   –     (151,997) Total stockholders' equity   6,771,616   307,720   151,375   (452,954)     6,777,757 Total liabilities and stockholders' equity $ 15,742,770 $ 471,257 $ 2,896,430 $ (496,423)   $ 18,614,034                         (a) Balances as of March 31, 2023                       (b) Eliminate investment in subsidiaries                       (c) Eliminate intercompany receivables and payables	Consolidating balance sheets by industry segment as of March 31, 2023 are as follows:       Moving & Storage Consolidated   Property & Casualty Insurance (a)   Life Insurance (a)   Eliminations     U-Haul Holding Company Consolidated       Assets:   (In thousands) Cash and cash equivalents $   2,034,242 $   11,276 $   15,006 $   –   $   2,060,524 Reinsurance recoverables and trade receivables, net   107,823   48,344   33,331   –     189,498 Inventories and parts, net   151,474   –   –   –     151,474 Prepaid expenses   241,711   –   –   –     241,711 Investments, fixed maturities and marketable equities   227,737   271,156   2,271,501   –     2,770,394 Investments, other   23,314   125,130   427,096   –     575,540 Deferred policy acquisition costs, net   –   –   128,463   –     128,463 Other assets   46,438   730   3,884   –     51,052 Right of use assets - financing, net   474,765   –   –   –     474,765 Right of use assets - operating, net   57,978   914   25   –     58,917 Related party assets   69,144   2,347   12,268   (35,451) (c)   48,308     3,434,626   459,897   2,891,574   (35,451)     6,750,646                         Investment in subsidiaries   426,779   –   –   (426,779) (b)   –                         Property, plant and equipment, at cost:                       Land   1,537,206   –   –   –     1,537,206 Buildings and improvements   7,088,810   –   –   –     7,088,810 Furniture and equipment   928,241   –   –   –     928,241 Rental trailers and other rental equipment   827,696   –   –   –     827,696 Rental trucks   5,278,340   –   –   –     5,278,340     15,660,293   –   –   –     15,660,293 Less:   Accumulated depreciation   (4,310,205)   –   –   –     (4,310,205) Total property, plant and equipment, net   11,350,088   –   –   –     11,350,088 Total assets $   15,211,493 $   459,897 $   2,891,574 $   (462,230)   $   18,100,734                         (a) Balances as of December 31, 2022                       (b) Eliminate investment in subsidiaries                       (c) Eliminate intercompany receivables and payables                       Consolidating balance sheets by industry segment as of March 31, 2023, continued       Moving & Storage   Property & Casualty Insurance (a)   Life   Eliminations     U-Haul Holding Company                             (In thousands) Liabilities:                       Accounts payable and accrued expenses $ 729,679 $ 4,470 $ 26,890 $ –   $ 761,039 Notes, loans and finance leases payable, net   6,108,042   –   –   –     6,108,042 Operating lease liabilities   57,418   928   27   –     58,373 Policy benefits and losses, claims and loss expenses payable   335,227   153,007   391,968   –     880,202 Liabilities from investment contracts   –   –   2,398,884   –     2,398,884 Other policyholders' funds and liabilities   –   2,702   5,530   –     8,232 Deferred income   52,282   –   –   –     52,282 Deferred income taxes, net   1,405,391   1,713   (77,615)   –     1,329,489 Related party liabilities   25,082   2,544   13,644   (41,270) (c)   – Total liabilities   8,713,121   165,364   2,759,328   (41,270)     11,596,543                         Stockholders' equity:                       Series preferred stock:                       Series A preferred stock   –   –   –   –     – Series B preferred stock   –   –   –   –     – Series A common stock   –   –   –   –     – Voting Common stock   10,497   3,301   2,500   (5,801) (b)   10,497 Non-Voting Common Stock   176   –   –   –     176 Additional paid-in capital   453,853   91,120   26,271   (117,601) (b)   453,643 Accumulated other comprehensive income (loss)   (291,442)   (14,720)   (225,904)   246,443 (b)   (285,623) Retained earnings   7,002,938   214,832   329,379   (544,001) (b)   7,003,148 Cost of common shares in treasury, net   (525,653)   –   –   –     (525,653) Cost of preferred shares in treasury, net   (151,997)   –   –   –     (151,997) Total stockholders' equity   6,498,372   294,533   132,246   (420,960)     6,504,191 Total liabilities and stockholders' equity $ 15,211,493 $ 459,897 $ 2,891,574 $ (462,230)   $ 18,100,734                         (a) Balances as of December 31, 2022                       (b) Eliminate investment in subsidiaries                       (c) Eliminate intercompany receivables and payables
Consolidated Statement of Operations by Industry Segment	Consolidating statement of operations by industry segment for the quarter ended June 30, 2023 are as follows:       Moving & Storage   Property & Casualty Insurance (a)   Life   Eliminations     U-Haul Holding Company     (Unaudited)     (In thousands) Revenues:                       Self-moving equipment rentals $ 1,000,079 $ – $ – $ (873) (c) $ 999,206 Self-storage revenues   198,961   –   –   –     198,961 Self-moving and self-storage products and service sales   100,872   –   –   –     100,872 Property management fees   9,177   –   –   –     9,177 Life insurance premiums   –   –   23,131   –     23,131 Property and casualty insurance premiums   –   21,047   –   (725) (c)   20,322 Net investment and interest income   27,295   6,792   31,511   (1,006) (b)   64,592 Other revenue   123,129   –   1,039   (121) (b)   124,047 Total revenues   1,459,513   27,839   55,681   (2,725)     1,540,308                         Costs and expenses:                       Operating expenses   748,283   11,307   5,366   (1,715) (b,c)   763,241 Commission expenses   106,927   –   –   –     106,927 Cost of sales   70,675   –   –   –     70,675 Benefits and losses   –   4,458   40,886   –     45,344 Amortization of deferred policy acquisition costs   –   –   8,045   –     8,045 Lease expense   8,102   92   28   (639) (b)   7,583 Depreciation, net of gains on disposals   137,814   –   –   –     137,814 Net losses on disposal of real estate   1,021   –   –   –     1,021 Total costs and expenses   1,072,822   15,857   54,325   (2,354)     1,140,650                         Earnings from operations before equity in earnings of subsidiaries   386,691   11,982   1,356   (371)     399,658                         Equity in earnings of subsidiaries   10,230   –   –   (10,230) (d)   –                         Earnings from operations   396,921   11,982   1,356   (10,601)     399,658 Other components of net periodic benefit costs   (365)   –   –   –     (365) Interest expense   (60,849)   –   (120)   371 (b)   (60,598) Pretax earnings   335,707   11,982   1,236   (10,230)     338,695 Income tax expense   (78,869)   (2,472)   (516)   –     (81,857) Net earnings available to common stockholders $ 256,838 $ 9,510 $ 720 $ (10,230)   $ 256,838                         (a) Balances for the quarter ended March 31, 2023                       (b) Eliminate intercompany lease / interest income                       (c) Eliminate intercompany premiums                       (d) Eliminate equity in earnings of subsidiaries	Consolidating statements of operations by industry for the quarter ended June 30, 2022 are as follows:       Moving & Storage   Property & Casualty Insurance (a)   Life   Eliminations     U-Haul Holding Company     (Unaudited)     (In thousands) Revenues:                       Self-moving equipment rentals $ 1,091,710 $ – $ – $ (935) (c) $ 1,090,775 Self-storage revenues   173,177   –   –   –     173,177 Self-moving and self-storage products and service sales   109,351   –   –   –     109,351 Property management fees   9,139   –   –   –     9,139 Life insurance premiums   –   –   25,781   –     25,781 Property and casualty insurance premiums   –   20,830   –   (858) (c)   19,972 Net investment and interest income   4,940   2,252   27,388   (1,007) (b)   33,573 Other revenue   135,281   –   934   (143) (b)   136,072 Total revenues   1,523,598   23,082   54,103   (2,943)     1,597,840                         Costs and expenses:                       Operating expenses   719,794   10,194   5,109   (1,930) (b,c)   733,167 Commission expenses   118,493   –   –   –     118,493 Cost of sales   79,671   –   –   –     79,671 Benefits and losses   –   4,379   35,378   –     39,757 Amortization of deferred policy acquisition costs   –   –   7,672   –     7,672 Lease expense   7,920   158   28   (631) (b)   7,475 Depreciation, net of gains on disposals   113,796   –   –   –     113,796 Net losses on disposal of real estate   2,307   –   –   –     2,307 Total costs and expenses   1,041,981   14,731   48,187   (2,561)     1,102,338                         Earnings from operations before equity in earnings of subsidiaries   481,617   8,351   5,916   (382)     495,502                         Equity in earnings of subsidiaries   12,009   –   –   (12,009) (d)   –                         Earnings from operations   493,626   8,351   5,916   (12,391)     495,502 Other components of net periodic benefit costs   (304)   –   –   –     (304) Interest expense   (50,061)   –   (120)   382 (b)   (49,799) Pretax earnings   443,261   8,351   5,796   (12,009)     445,399 Income tax expense   (104,916)   (1,755)   (383)   –     (107,054) Net earnings available to common stockholders $ 338,345 $ 6,596 $ 5,413 $ (12,009)   $ 338,345                         (a) Balances for the quarter ended March 31, 2022                       (b) Eliminate intercompany lease / interest income                       (c) Eliminate intercompany premiums                       (d) Eliminate equity in earnings of subsidiaries
Consolidated Cash Flow Statement by Industry Segment	Consolidating cash flow statements by industry segment for the quarter ended June 30, 2023 are as follows:     Moving & Storage Consolidated   Property & Casualty Insurance (a)   Life Insurance (a)   Elimination     U-Haul Holding Company Consolidated     (Unaudited) Cash flows from operating activities:   (In thousands) Net earnings $   256,838 $   9,510 $   720 $   (10,230)   $   256,838 Earnings from consolidated entities   (10,230)   –   –   10,230     – Adjustments to reconcile net earnings to the cash provided by operations:                       Depreciation   193,475   –   –   –     193,475 Amortization of deferred policy acquisition costs   –   –   8,045   –     8,045 Amortization of premiums and accretion of discounts related to investments, net   –   383   4,011   –     4,394 Amortization of debt issuance costs   1,456   –   –   –     1,456 Interest credited to policyholders   –   –   17,538   –     17,538 Provision for allowance (recoveries) for losses on trade receivables, net   631   (39)   –   –     592 Provision for allowance for inventories and parts reserve   (327)   –   –   –     (327) Net gains on disposal of personal property   (55,661)   –   –   –     (55,661) Net losses on disposal of real estate   1,021   –   –   –     1,021 Net gains on sales of investments   –   (34)   (1,880)   –     (1,914) Net gains on equity investments   –   (2,429)   –   –     (2,429) Deferred income taxes, net   32,087   2,085   (64)   –     34,108 Net change in other operating assets and liabilities:                       Reinsurance recoverables and trade receivables   (17,964)   (411)   940   –     (17,435) Inventories and parts   (13,068)   –   –   –     (13,068) Prepaid expenses   9,870   –   –   –     9,870 Capitalization of deferred policy acquisition costs   –   –   (3,177)   –     (3,177) Other assets and right-of-use assets - operating, net   (8,769)   (231)   (957)   –     (9,957) Related party assets   3,645   (513)   –   –     3,132 Accounts payable and accrued expenses and operating lease liabilities   52,573   (1,166)   (18,295)   –     33,112 Policy benefits and losses, claims and loss expenses payable   (7,590)   (4,047)   (461)   –     (12,098) Other policyholders' funds and liabilities   –   (267)   4,253   –     3,986 Deferred income   12,441   –   (442)   –     11,999 Related party liabilities   1,547   655   (5)   –     2,197 Net cash provided by operating activities   451,975   3,496   10,226   –     465,697                         Cash flows from investing activities:                       Escrow deposits   (361)   –   –   –     (361) Purchases of:                       Property, plant and equipment   (773,577)   –   –   –     (773,577) Short term investments   –   (9,216)   (741)   –     (9,957) Fixed maturities investments   –   (495)   (2,756)   –     (3,251) Equity securities   –   (242)   –   –     (242) Real estate   (16)   –   (399)   –     (415) Mortgage loans   –   (7,300)   (45,150)   –     (52,450) Proceeds from sales and paydowns of:                       Property, plant and equipment   193,455   –   –   –     193,455 Short term investments   –   11,676   69   –     11,745 Fixed maturities investments   224,999   3,490   108,370   –     336,859 Equity securities   –   236   –   –     236 Preferred stock   –   913   –   –     913 Mortgage loans   –   204   8,173   –     8,377 Net cash (used) provided by investing activities   (355,500)   (734)   67,566   –     (288,668)     (page 1 of 2) (a) Balance for the period ended March 31, 2023                         Consolidating cash flow statements by industry segment for the quarter ended June 30, 2023, continued       Moving & Storage   Property &   Life   Elimination     U-Haul Holding Company     (Unaudited) Cash flows from financing activities:   (In thousands) Borrowings from credit facilities   445,493   –   –   –     445,493 Principal repayments on credit facilities   (232,824)   –   –   –     (232,824) Payments of debt issuance costs   (2,688)   –   –   –     (2,688) Finance lease payments   (34,168)   –   –   –     (34,168) Securitization deposits   79   –   –   –     79 Series N Non-Voting Common Stock dividends paid   (7,059)   –   –   –     (7,059) Investment contract deposits   –   –   51,239   –     51,239 Investment contract withdrawals   –   –   (83,331)   –     (83,331) Net cash provided (used) by financing activities   168,833   –   (32,092)   –     136,741                         Effects of exchange rate on cash   2,830   –   –   –     2,830                         Increase (decrease) in cash and cash equivalents   268,138   2,762   45,700   –     316,600 Cash and cash equivalents at beginning of period   2,034,242   11,276   15,006   –     2,060,524 Cash and cash equivalents at end of period $   2,302,380 $   14,038 $   60,706 $   –   $   2,377,124     (page 2 of 2) (a) Balance for the period ended March 31, 2023	Consolidating cash flow statements by industry segment for the quarter ended June 30, 2022 are as follows:       Moving & Storage Consolidated   Property & Casualty Insurance (a)   Life Insurance (a)   Elimination     U-Haul Holding Company Consolidated     (Unaudited) Cash flows from operating activities:   (In thousands) Net earnings $   338,345 $   6,596 $   5,413 $   (12,009)   $   338,345 Earnings from consolidated entities   (12,009)   –   –   12,009     – Adjustments to reconcile net earnings to cash provided by operations:                       Depreciation   178,144   –   –   –     178,144 Amortization of deferred policy acquisition costs   –   –   7,672   –     7,672 Amortization of premiums and accretion of discounts related to investments, net   –   421   4,508   –     4,929 Amortization of debt issuance costs   1,473   –   –   –     1,473 Interest credited to policyholders   –   –   15,157   –     15,157 Provision for allowance (recoveries) for losses on trade receivables, net   (6,075)   (76)   –   –     (6,151) Provision for allowance for inventories and parts reserve   4,646   –   –   –     4,646 Net gains on disposal of personal property   (64,348)   –   –   –     (64,348) Net gains on disposal of real estate   2,307   –   –   –     2,307 Net gains on sales of investments   –   (31)   299   –     268 Net gains on equity investments   –   1,551   –   –     1,551 Deferred income taxes   61,948   127   1,418   –     63,493 Net change in other operating assets and liabilities:                       Reinsurance recoverables and trade receivables   18,458   (2,107)   (457)   –     15,894 Inventories and parts   (10,347)   –   –   –     (10,347) Prepaid expenses   4,935   –   –   –     4,935 Capitalization of deferred policy acquisition costs   –   –   (7,398)   –     (7,398) Other assets and right-of-use assets - operating, net   2,177   (40)   (202)   –     1,935 Related party assets   747   (263)   –   –     484 Accounts payable and accrued expenses and operating lease liabilities   78,549   (549)   (3,324)   –     74,676 Policy benefits and losses, claims and loss expenses payable   8,875   (1,237)   (1,595)   –     6,043 Other policyholders' funds and liabilities   –   (159)   1,346   –     1,187 Deferred income   14,501   –   (53)   –     14,448 Related party liabilities   1,251   517   260   –     2,028 Net cash provided by operating activities   623,577   4,750   23,044   –     651,371                         Cash flows from investing activities:                       Escrow deposits   4,789   –   –   –     4,789 Purchases of:                       Property, plant and equipment   (646,137)   –   –   –     (646,137) Short term investments   –   (21,966)   (51)   –     (22,017) Fixed maturities investments   –   (9,839)   (26,649)   –     (36,488) Equity securities   –   (1,366)   –   –     (1,366) Mortgage loans   –   (6,975)   (35,586)   –     (42,561) Proceeds from sales and paydowns of:                       Property, plant and equipment   159,180   –   –   –     159,180 Short term investments   –   18,073   –   –     18,073 Fixed maturities investments   –   6,852   48,956   –     55,808 Equity securities   –   362   –   –     362 Mortgage loans   –   8,374   23,971   –     32,345 Net cash (used) provided by investing activities   (482,168)   (6,485)   10,641   –     (478,012)     (page 1 of 2) (a) Balance for the period ended March 31, 2022                       Consolidating cash flow statements by industry segment for the quarter ended June 30, 2022, continued       Moving & Storage   Property &   Life   Elimination     U-Haul Holding Company     (Unaudited) Cash flows from financing activities:   (In thousands) Borrowings from credit facilities   393,264   –   –   –     393,264 Principal repayments on credit facilities   (145,369)   –   –   –     (145,369) Payment of debt issuance costs   (1,069)   –   –   –     (1,069) Finance lease payments   (34,982)   –   –   –     (34,982) Voting Common Stock dividends paid   (9,804)   –   –   –     (9,804) Investment contract deposits   –   –   85,767   –     85,767 Investment contract withdrawals   –   –   (62,911)   –     (62,911) Net cash provided by financing activities   202,040   –   22,856   –     224,896                         Effects of exchange rate on cash   (4,121)   –   –   –     (4,121)                         Increase (decrease) in cash and cash equivalents   339,328   (1,735)   56,541   –     394,134 Cash and cash equivalents at beginning of period   2,643,213   10,800   50,124   –     2,704,137 Cash and cash equivalents at end of period $   2,982,541 $   9,065 $   106,665 $   –   $   3,098,271     (page 2 of 2) (a) Balance for the period ended March 31, 2022