Commercial Loans Held-for-Investment (Details)	3 Months Ended	12 Months Ended
Mar. 31, 2018 USD ($) loan	Dec. 31, 2017 USD ($) loan
Accounts, Notes, Loans and Financing Receivable
Carrying value	$ 184,255,000	$ 191,808,000
Commercial Portfolio Segment
Accounts, Notes, Loans and Financing Receivable
Allowance for loan losses	$ 0	$ 0
Commercial Portfolio Segment \| Mezzanine Loans
Accounts, Notes, Loans and Financing Receivable
Number of loans \| loan	7	8
Principal Balance	$ 184,311,000	$ 191,894,000
Unamortized (fees)/ costs, net	(56,000)	(86,000)
Carrying value	$ 184,255,000	$ 191,808,000
Weighted Average Coupon	8.72%	8.52%
Weighted Average Years to Maturity	1 year 1 month	1 year 2 months

Loans and Leases Receivable, Weighted Average Coupon Rate

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Loans and Leases Receivable, Weighted Average Years to Maturity

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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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No definition available.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

+ References

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Amount, before allowance and fees, of loans and leases receivable. Excludes loans and leases covered under loss sharing agreements.

+ References

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- Definition

Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

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- Definition

Indicates the number of mortgages under each classification.

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Amount of deferred fees paid by borrowers and unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of loans that are being amortized into income as an adjustment to yield. Excludes amounts for loans and leases covered under loss sharing agreements.

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