Related Party Assets (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012		Mar. 31, 2012
Related party assets:
U-Haul notes, receivables and interest	$ 68,588		$ 68,798
Notes receivable	72,852		195,426
U-Haul interest receivable	14,233		18,667
U-Haul receivables	16,533		33,492
Other	1,299	[1]	(226)	[1]
Related party assets	173,505		316,157
SAC Holdings
Related party assets:
Notes receivable	72,852		195,426
U-Haul interest receivable	14,233		18,667
U-Haul receivables	14,096		30,297
Private Mini
Related party assets:
U-Haul notes, receivables and interest	68,588		68,798
Mercury
Related party assets:
U-Haul receivables	2,437		3,195
Insurance subsidiaries
Related party assets:
Other	$ 1,299	[1]	$ (226)	[1]

[1] Timing differences for intercompany balances with insurance subsidiaries