Schedule II - AMERCO and Consolidated Subsidiaries, Valuation and Qualifying Accounts (Details) - Amerco [Member] - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Allowance for doubtful accounts (deducted from trade receivable) [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	$ 585	$ 790	$ 958
Additions charged to cost and expenses	913	967	994
Additions charged to other accounts
Deductions	(959)	(1,172)	(1,162)
Balance at year end	539	585	790
Allowance for obsolescence (deducted from inventory) [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	1,597	1,384	2,487
Additions charged to cost and expenses	1,218	213
Additions charged to other accounts
Deductions	(765)		(1,103)
Balance at year end	2,050	1,597	1,384
Allowance for LIFO (deducted from inventory) [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	13,463	15,019	14,788
Additions charged to cost and expenses	877		231
Additions charged to other accounts
Deductions		(1,556)
Balance at year end	14,340	13,463	15,019
Allowance for probable losses (deducted from mortgage loans) [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	368	370	370
Additions charged to cost and expenses	125
Additions charged to other accounts
Deductions		(2)
Balance at year end	$ 493	$ 368	$ 370