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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, net of any write-downs taken for collection uncertainty on the part of the holder. 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 myriad other features and characteristics. In addition, amount also includes total debt and equity financial instruments including: securities held-to-maturity and securities available-for-sale.

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Carrying amount as of the balance sheet date of investments in land and buildings held for sale, including real estate considered to be inventory of the entity.

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Real Estate Investment Property, Held for Use, Net

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Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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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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A valuation allowance for financing receivables that are expected to be uncollectible.

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Carrying amount as of the balance sheet date, net of valuation allowances and impairment losses, of costs of land expected to be developed in the near term plus capitalized costs of development, for purposes of selling completed units to home buyers or commercial or industrial entities..

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Debt Obligations, net - Collateral Assets (Details) - USD ($)	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017
Debt Instrument [Line Items]
Real estate, net	$ 1,621,004,000	$ 1,771,019,000
Real estate available and held for sale	253,336,000	22,551,000
Land and development, net	616,350,000	598,218,000
Loans receivable and other lending investments, net	894,846,000	988,224,000
Other investments	521,999,000	304,275,000
Cash and other assets	763,878,000	1,329,990,000
Total assets	4,671,413,000	5,014,277,000
Carrying amount of assets held by entities pledged as collateral	406,200,000
General reserve for loan losses	53,298,000	53,395,000	$ 69,466,000	$ 78,489,000
Loan participations	796,536,000	870,992,000
Loan Participations
Debt Instrument [Line Items]
Loan participations	25,100,000	22,500,000
Collectively Evaluated for Impairment
Debt Instrument [Line Items]
General reserve for loan losses	12,410,000	13,000,000
Loan participations	770,924,000	844,662,000
Secured Debt \| 2015 $325 million Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	325,000,000				$ 325,000,000
Collateral Assets
Debt Instrument [Line Items]
Real estate, net	1,533,390,000	1,620,008,000
Real estate available and held for sale	219,184,000	1,055,000
Land and development, net	42,300,000	12,300,000
Loans receivable and other lending investments, net	431,189,000	498,524,000
Other investments	0	0
Cash and other assets	6,601,000	0
Total assets	2,232,664,000	2,131,887,000
Non-Collateral Assets
Debt Instrument [Line Items]
Real estate, net	87,614,000	151,011,000
Real estate available and held for sale	34,152,000	21,496,000
Land and development, net	574,050,000	585,918,000
Loans receivable and other lending investments, net	450,988,000	480,154,000
Other investments	521,999,000	304,275,000
Cash and other assets	757,277,000	1,329,990,000
Total assets	$ 2,426,080,000	$ 2,872,844,000