Schedule II - AMERCO and Consolidated Subsidiaries, Valuation and Qualifying Accounts (Details) - Amerco [Member] - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Allowance for doubtful accounts (deducted from trade receivable) [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	$ 549	$ 496	$ 585
Additions charged to cost and expenses	731	1,550	886
Additions charged to other accounts	0	0	0
Deductions	(745)	(1,497)	(929)
Balance at year end	535	549	496
Allowance for obsolescence (deducted from inventory) [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	2,322	5,329	2,050
Additions charged to cost and expenses	741	0	3,279
Additions charged to other accounts	0	0	0
Deductions	0	(3,007)	0
Balance at year end	3,063	2,322	5,329
Allowance for LIFO (deducted from inventory) [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	18,987	16,126	14,340
Additions charged to cost and expenses	0	2,861	1,786
Additions charged to other accounts	0	0	0
Deductions	(101)	0	0
Balance at year end	18,886	18,987	16,126
Allowance for probable losses (deducted from mortgage loans) [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	493	618	493
Additions charged to cost and expenses	0	0	125
Additions charged to other accounts	0	0	0
Deductions	0	(125)	0
Balance at year end	$ 493	$ 493	$ 618