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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 29
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953659-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 30
-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953664-111524

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+ References

No definition available.

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Amount representing an agreement for an unconditional promise by the maker to pay the entity (holder) a definite sum of money at a future date. Such amount may include accrued interest receivable in accordance with the terms of the note. The note also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among a myriad of other features and characteristics. Excludes amounts related to receivables held-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.10(3))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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Loans Receivable and Other Lending Investments, net (Credit Characteristics for Performing Loans) (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016 USD ($)	Dec. 31, 2014	Dec. 31, 2015 USD ($)
Recorded Investments in loans, presented by class and by credit quality, as indicated by risk rating
Loans	$ 1,710,449		$ 1,656,839
Senior mortgages
Recorded Investments in loans, presented by class and by credit quality, as indicated by risk rating
Loans	1,015,036		980,349
Corporate/Partnership loans
Recorded Investments in loans, presented by class and by credit quality, as indicated by risk rating
Loans	669,613		647,451
Subordinate mortgages
Recorded Investments in loans, presented by class and by credit quality, as indicated by risk rating
Loans	25,800		29,039
Real Estate Finance
Recorded Investments in loans, presented by class and by credit quality, as indicated by risk rating
Loans	$ 1,569,029		1,524,347
Weighted Average Risk Ratings	3.13	3.15
Real Estate Finance \| Senior mortgages
Recorded Investments in loans, presented by class and by credit quality, as indicated by risk rating
Loans	$ 879,019		853,595
Weighted Average Risk Ratings	2.96	2.96
Real Estate Finance \| Corporate/Partnership loans
Recorded Investments in loans, presented by class and by credit quality, as indicated by risk rating
Loans	$ 664,210		641,713
Weighted Average Risk Ratings	3.31	3.37
Real Estate Finance \| Subordinate mortgages
Recorded Investments in loans, presented by class and by credit quality, as indicated by risk rating
Loans	$ 25,800		$ 29,039
Weighted Average Risk Ratings	3.92	3.64
Minimum
Recorded Investments in loans, presented by class and by credit quality, as indicated by risk rating
Risk rating	1
Maximum
Recorded Investments in loans, presented by class and by credit quality, as indicated by risk rating
Risk rating	5