Schedule II, AMERCO and Consolidated Subsidiaries, Valuation and Qualifying Accounts (Details) (AMERCO [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Allowance for doubtful accounts (deducted from trade receivable) [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	$ 958	$ 994	$ 1,128
Additions charged to cost and expenses	994	958	1,184
Additions charged to other accounts
Deductions	(1,162)	(994)	(1,318)
Balance at year end	790	958	994
Allowance for obsolescence (deducted from inventory) [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	2,487	1,711	730
Additions charged to cost and expenses		776	981
Additions charged to other accounts
Deductions	(1,103)
Balance at year end	1,384	2,487	1,711
Allowance for LIFO (deducted from inventory) [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	14,788	14,693	14,541
Additions charged to cost and expenses	231	95	152
Additions charged to other accounts
Deductions
Balance at year end	15,019	14,788	14,693
Allowance for probable losses (deducted from mortgage loans) [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	370	370	370
Additions charged to cost and expenses
Additions charged to other accounts
Deductions
Balance at year end	$ 370	$ 370	$ 370