Condensed Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
Jun. 30, 2012	Jun. 30, 2011
Comprehensive income (loss) (pretax):
Net earnings	$ 127,388	$ 125,730
Comprehensive income (loss) (tax effect):
Net earnings	(46,819)	(47,507)
Comprehensive income (loss) (net of tax):
Net earnings	80,569	78,223
Other comprehensive income (loss):
Foreign currency translation (pretax)	(1,929)	992
Foreign currency translation (tax effect)	0	0
Foreign currency translation (net of tax)	(1,929)	992
Unrealized gain (loss) on investments (pretax)	1,873	(5,378)
Unrealized gain (loss) on investments (tax effect)	(580)	2,001
Unrealized gain (loss) on investments (net of tax)	1,293	(3,377)
Change in fair value of cash flow hedges (pretax)	(515)	(3,860)
Change in fair value of cash flow hedges (tax effect)	196	1,467
Change in fair value of cash flow hedges (net of tax)	(319)	(2,393)
Total comprehensive income (loss) (pretax)	126,817	117,484
Total comprehensive income (loss) (tax effect)	(47,203)	(44,039)
Total comprehensive income (loss) (net of tax)	$ 79,614	$ 73,445

Name:	uhal_OtherComprehensiveIncomeLossAbstract
Namespace Prefix:	uhal_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the reporting entity. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, but excludes any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent.