VARIABLE INTERESTS (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
Jun. 30, 2011
Variable Interests in Unconsolidated Real Estate Joint Ventures:
Number of interests in unconsolidated VIE joint ventures	2
Equity interests in unconsolidated VIE joint ventures, low end of range (as a percent)	18.00%
Equity interests in unconsolidated VIE joint ventures, high end of range (as a percent)	39.00%
Voting rights in unconsolidated VIE joint ventures (as a percent)	50.00%
Management fees charged from unconsolidated VIE joint ventures (as a percent)	6.00%
Corporate Joint Venture [Member]
Variable Interests in Unconsolidated Real Estate Joint Ventures:
Investment balance	$ 352
Balance of guaranteed loan	9,145
Payables to company	8,563
Maximum exposure to loss	18,060
Difference	(18,060)
Extra Space of Montrose Avenue LLC
Variable Interests in Unconsolidated Real Estate Joint Ventures:
Investment balance	1,214
Balance of guaranteed loan	4,838
Payables to company	2,469
Maximum exposure to loss	8,521
Difference	(8,521)
Extra Space of Sacramento One LLC
Variable Interests in Unconsolidated Real Estate Joint Ventures:
Investment balance	(862)
Balance of guaranteed loan	4,307
Payables to company	6,094
Maximum exposure to loss	9,539
Difference	$ (9,539)

The high end of the range of the percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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The low end of the range of the percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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Represents the number of unconsolidated VIE joint ventures in which the entity holds interest.

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Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

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The percentage charged for managing real estate properties.

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The reporting entity's maximum amount of exposure to loss as a result of its involvement with the Variable Interest Entity (VIE).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

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