Self-Insurance Reserves (Details) (Property liability for rental equipment, U-Haul, USD $) In Millions, unless otherwise specified	12 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Property liability for rental equipment \| U-Haul
Liability for Future Policy Benefit, by Product Segment [Line Items]
Self insurance reserve	$ 380.8	$ 380.1
Reduced self-insurance reserve	5.0	20.0
Accrued insurance, noncurrent	8.1	6.7
Estimated insurance recoveries	$ 0.5	$ 0.1

Carrying value as of the balance sheet date of obligations incurred through that date and due beyond one year (or beyond one operating cycle if longer) to insurance entities to mitigate potential loss from various risks or to satisfy a promise to provide certain coverages to employees.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.24)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 24

-Article 5

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying amount as of the balance sheet date of amounts expected to be recovered under the terms of insurance contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.17)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 17

-Article 5

+ Details

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- Definition

The increase (decrease) during the period in the carrying amount of accrued known and estimated losses incurred for which no insurance coverage exists, and for which a claim has been made or is probable of being asserted, typically arising from workmen's' compensation-type of incidents and personal injury to nonemployees from accidents on the entity's property.

+ References

No definition available.

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Carrying amount (including both current and noncurrent portions) of accrued known and estimated losses incurred as of the balance sheet date for which no insurance coverage exists, and for which a claim has been made or is probable of being asserted, typically arising from workmen's compensation-type of incidents and personal injury to nonemployees from accidents on the entity's property.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant