Represents the amount of accretion liability arised during the period.

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Represents the acrrued accretion expense as of the balance sheet date.

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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 self-storage facilities owned and operated.

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Represents the number of real estate properties that were sold.

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Represents information pertaining to the number of parcels into which the subdivision of land is done reporting period.

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Represents information pertaining to the number of parcels of land sold during the reporting period.

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Represents the option to call ownership interest of another member.

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Represents the option to put ownership interest in the venture.

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Represents the period of option to call ownership interest of another member.

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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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The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

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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 outflow associated with the purchase of real estate held for investment purposes.

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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 value of all consideration given or received by the Entity in the significant acquisition or disposal.

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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			12 Months Ended
	Jun. 30, 2014 USD ($) facility	Mar. 31, 2016 USD ($) property	Dec. 31, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($) item	Dec. 31, 2013 USD ($)	Dec. 31, 2008 property	Oct. 02, 2015 GBP (£)	Oct. 02, 2015 USD ($)	Dec. 31, 2013 GBP (£)	Dec. 31, 2013 USD ($)
Interests in Consolidated Real Estate Joint Ventures
Reduction to additional paid in capital				$ 178
Exterior St
Interests in Consolidated Real Estate Joint Ventures
Option to put ownership interest in the venture		$ 37,800
Period of option to call ownership interest of another member		1 year
Period of option to put ownership interest in venture		1 year
Option to call ownership interest of another member		$ 37,800
Cropsey Ave
Interests in Consolidated Real Estate Joint Ventures
Option to put ownership interest in the venture		$ 20,400
Period of option to call ownership interest of another member		1 year
Period of option to put ownership interest in venture		1 year
Option to call ownership interest of another member		$ 20,400
Tilloston Ave
Interests in Consolidated Real Estate Joint Ventures
Ownership interest held by the entity (as a percent)		51.00%
Minority ownership interest (as a percent)		49.00%
Option to put ownership interest in the venture		$ 17,000
Period of option to call ownership interest of another member		1 year
Period of option to put ownership interest in venture		1 year
Option to call ownership interest of another member		$ 17,000
Accretion liability		17,000
Accrued accretion expenses		13,400
Total assets		22,200
Total liabilities		15,200
Jamaica Ave
Interests in Consolidated Real Estate Joint Ventures
Accretion liability		12,500
Total liabilities		$ 13,400
USIFB, LLP
Interests in Consolidated Real Estate Joint Ventures
Ownership interest held by the entity (as a percent)							97.00%
Number of self-storage facilities owned and operated \| property							2
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 purchase or sale price								£ 6.5	$ 9,900
SRLLC
Interests in Consolidated Real Estate Joint Ventures
Ownership interest held by the entity (as a percent)		90.00%
Total assets		$ 16,700
Total liabilities		13,100
Carrying amount of mortgage loans		13,100
Amount of mortgage loan commitment		$ 14,600
Payments to acquire land for development						$ 13,100
Number of parcels in which the subdivision of land is done reporting period \| item					2
Number of parcel sold \| item					1
Proceeds from sales of facilities, net					$ 6,500
SNL
Interests in Consolidated Real Estate Joint Ventures
Ownership interest held by the entity (as a percent)		90.00%
Number of self-storage facilities owned and operated \| property		2
Total assets		$ 31,300
Total liabilities		20,100
Carrying amount of mortgage loans		19,000
Amount of mortgage loan commitment		$ 22,600
Jamaica Ave
Interests in Consolidated Real Estate Joint Ventures
Ownership interest held by the entity (as a percent)		51.00%
Minority ownership interest (as a percent)		49.00%
Period of option to call ownership interest of another member		1 year
Option to call ownership interest of another member		$ 12,500
Total assets		31,800
Jamaica Ave \| Jamaica Ave
Interests in Consolidated Real Estate Joint Ventures
Option to put ownership interest in the venture		$ 12,500
Period of option to put ownership interest in venture		1 year
Exterior St
Interests in Consolidated Real Estate Joint Ventures
Ownership interest held by the entity (as a percent)		51.00%
Minority ownership interest (as a percent)		49.00%
Accretion liability		$ 37,800
Accrued accretion expenses		2,100
Total assets		21,500
Total liabilities		$ 2,100
Cropsey Ave
Interests in Consolidated Real Estate Joint Ventures
Ownership interest held by the entity (as a percent)		51.00%
Minority ownership interest (as a percent)		49.00%
Accretion liability		$ 20,400
Accrued accretion expenses		4,500
Total assets		13,300
Total liabilities		$ 4,600