Additional Paid In Capital and Insurance Subsidiaries Activity (Details) (USD $)	3 Months Ended
	Jun. 30, 2011
Additional paid in capital:
Payments for repurchase preferred stock	$ 144,289,000
Series A preferred stock redemption date	Jun. 01, 2011
Insurance subsidiaries
Additional paid in capital:
Payments for repurchase preferred stock	7,700,000
Reduction of insurance company holdings	5,900,000
AMERCO /NV/
Additional paid in capital:
Payments for repurchase preferred stock	151,997,000
Amerco Payment for Stock
Additional paid in capital:
Prior to redemption additional paid-in capital cost	146,300,000
Payments for repurchase preferred stock	$ 152,500,000