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Represents the amount of loan commitment which are secured by a mortgage on the real estate assets.

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Represents the number of real estate properties that were sold.

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Represents the debt assumed on real estate acquisition.

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Amount of long-term debt due after one year or the normal operating cycle, if longer, assumed at the acquisition date.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Amount before tax of foreign currency transaction realized and unrealized gain (loss) recognized in the income statement.

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The difference between the carrying value and the sale price of real estate or properties that were intended to be sold or held for capital appreciation or rental income. This element refers to the gain (loss) included in earnings and not to the cash proceeds of the sale. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method.

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Total carrying amount of mortgage loans as of the balance sheet date.

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Amount of increase in noncontrolling interest from subsidiary issuance of equity interests to noncontrolling interest holders.

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The cash inflow from the sale of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale.

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Cash received from the sale of real estate that is held for investment, that is, it is part of an investing activity during the period.

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The carrying amount of the consolidated Variable Interest Entity's assets included in the reporting entity's statement of financial position.

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The carrying amount of the consolidated Variable Interest Entity's liabilities included in the reporting entity's statement of financial position.

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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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NONCONTROLLING INTERESTS - Interests in Consolidated Real Estate Joint Ventures (Details) $ in Thousands, £ in Millions			1 Months Ended	3 Months Ended	6 Months Ended		12 Months Ended
	Oct. 02, 2015 GBP (£)	Oct. 02, 2015 USD ($)	Jun. 30, 2014 USD ($) facility	Dec. 31, 2015 USD ($)	Jun. 30, 2016 USD ($) facility	Jun. 30, 2015 USD ($)	Dec. 31, 2008 property	Dec. 31, 2013 GBP (£)	Dec. 31, 2013 USD ($)
Interests in Consolidated Real Estate Joint Ventures
Reduction to additional paid in capital					$ 4,396	$ 178
2880 Exterior St. LLC
Interests in Consolidated Real Estate Joint Ventures
Option to call ownership interest of another member					37,800
Accretion liability					6,300
3068 Cropsey Ave LLC
Interests in Consolidated Real Estate Joint Ventures
Option to call ownership interest of another member					20,400
Accretion liability					6,800
2301 Tillotson Ave LLC
Interests in Consolidated Real Estate Joint Ventures
Option to call ownership interest of another member					17,000
Accretion liability					$ 17,000
VIE
Interests in Consolidated Real Estate Joint Ventures
Number of self-storage facilities owned and operated \| facility					7
Total assets					$ 198,292
Total liabilities					$ 102,279
Period of option to call ownership interest of another member					1 year
Period of option to put ownership interest in venture					1 year
VIE \| 444 55th Street Holdings, LLC
Interests in Consolidated Real Estate Joint Ventures
Number of self-storage facilities owned and operated \| facility					1
Ownership interest held by the entity (as a percent)					90.00%
Total assets					$ 76,991
Total liabilities					35,079
Assumed mortgage debt, at fair value					35,000
Outstanding principal balance of mortgage debt assumed on acquisitions					32,500
Premium on debt assumed on one of the acquisitions					$ 2,500
Interest rate (as a percent)					4.68%
VIE \| 2880 Exterior St. LLC
Interests in Consolidated Real Estate Joint Ventures
Number of self-storage facilities owned and operated \| facility					1
Ownership interest held by the entity (as a percent)					51.00%
Total assets					$ 25,670
Total liabilities					6,295
Option to put ownership interest in the venture					$ 37,800
VIE \| 3068 Cropsey Ave LLC
Interests in Consolidated Real Estate Joint Ventures
Number of self-storage facilities owned and operated \| facility					1
Ownership interest held by the entity (as a percent)					51.00%
Total assets					$ 16,401
Total liabilities					7,718
Option to put ownership interest in the venture					$ 20,400
VIE \| 2301 Tillotson Ave LLC
Interests in Consolidated Real Estate Joint Ventures
Number of self-storage facilities owned and operated \| facility					1
Ownership interest held by the entity (as a percent)					51.00%
Total assets					$ 31,330
Total liabilities					19,392
Option to put ownership interest in the venture					$ 17,000
VIE \| CS SNL New York Ave LLC
Interests in Consolidated Real Estate Joint Ventures
Number of self-storage facilities owned and operated \| facility					1
Ownership interest held by the entity (as a percent)					90.00%
Total assets					$ 13,753
Total liabilities					$ 9,256
VIE \| 186 Jamaica Ave LLC
Interests in Consolidated Real Estate Joint Ventures
Number of self-storage facilities owned and operated \| facility					1
Ownership interest held by the entity (as a percent)					90.00%
Total assets					$ 17,677
Total liabilities					$ 11,530
VIE \| Shirlington Rd LLC
Interests in Consolidated Real Estate Joint Ventures
Number of self-storage facilities owned and operated \| facility					1
Ownership interest held by the entity (as a percent)					90.00%
Total assets					$ 16,470
Total liabilities					13,009
USIFB, LLP
Interests in Consolidated Real Estate Joint Ventures
Number of self-storage facilities owned and operated \| property							2
Ownership interest held by the entity (as a percent)							97.00%
Carrying amount of mortgage loans								£ 4.1	$ 6,800
Gain (loss) from sale of land				$ 3,000
Number of assets sold \| facility			1
Proceeds from sales of facilities, net			$ 7,000
Gain from sale of real estate				3,000
Foreign currency translation loss				$ (1,200)
Aggregate sale price	£ 6.5	$ 9,900
SRLLC
Interests in Consolidated Real Estate Joint Ventures
Carrying amount of mortgage loans					13,100
Amount of mortgage loan commitment					14,600
SNL
Interests in Consolidated Real Estate Joint Ventures
Carrying amount of mortgage loans					9,100
Amount of mortgage loan commitment					9,800
SNL II
Interests in Consolidated Real Estate Joint Ventures
Carrying amount of mortgage loans					11,300
Amount of mortgage loan commitment					$ 12,800