Investment in Storage Facilities - Summary of Activity in Storage Facilities (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2014
Cost:
Beginning balance	$ 1,864,637
Acquisition of storage facilities	93,854
Improvements and equipment additions	2,987
Net increase in construction in progress	1,671
Dispositions and impairments	(90)
Ending balance	1,963,059
Accumulated Depreciation:
Beginning balance	366,472
Depreciation expense during the period	11,276
Dispositions	(63)
Ending balance	$ 377,685

Improvements and equipment additions.

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Real estate investment property depreciation dispositions.

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Real Estate Net Increase Decrease In Construction In Progress

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No definition available.

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The capitalized costs incurred during the period (excluded from amortization) to purchase, lease or otherwise acquire an unproved property, including costs of lease bonuses and options to purchase or lease properties, the portion of costs applicable to minerals when land including mineral rights is purchased in fee, brokers' fees, recording fees, legal costs, and other costs incurred in acquiring properties.

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The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

+ References

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

-Publisher FASB

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- Definition

Amount of real estate investments sold for entities with a substantial portion of business acquiring and holding investment real estate.

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The cumulative amount of depreciation for real estate property held for investment purposes.

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Amount of real estate investment property which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments.

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