Loans Held-for-Investment (Details) $ in Thousands	12 Months Ended
Dec. 31, 2019 USD ($) loan	Dec. 31, 2018 USD ($) loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Threshold period when delinquent loans are placed on nonaccrual status	90 days
Unpaid principal balance	$ 4,257,145	$ 3,193,641
Unamortized (discount) premium	(124)	(151)
Unamortized net deferred origination fees	(30,809)	(25,577)
Loans held-for-investment	4,226,212	3,167,913
Unfunded commitments	$ 748,878	$ 626,155
Number of loans \| loan	120	92
Weighted average coupon	5.40%	6.50%
Weighted average years to maturity	1 year 9 months 18 days	2 years
First Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid principal balance	$ 4,229,194	$ 3,147,310
Unamortized (discount) premium	(124)	(151)
Unamortized net deferred origination fees	(30,788)	(25,577)
Loans held-for-investment	4,198,282	3,121,582
Unfunded commitments	$ 748,878	$ 626,155
Number of loans \| loan	117	88
Weighted average coupon	5.40%	6.40%
Weighted average years to maturity	1 year 9 months 18 days	2 years
Second Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid principal balance	$ 13,503	$ 31,679
Unamortized (discount) premium	0	0
Unamortized net deferred origination fees	(21)	0
Loans held-for-investment	13,482	31,679
Unfunded commitments	$ 0	$ 0
Number of loans \| loan	2	3
Weighted average coupon	11.70%	11.40%
Weighted average years to maturity	2 years	1 year 10 months 24 days
Junior Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid principal balance	$ 14,448	$ 14,652
Unamortized (discount) premium	0	0
Unamortized net deferred origination fees	0	0
Loans held-for-investment	14,448	14,652
Unfunded commitments	$ 0	$ 0
Number of loans \| loan	1	1
Weighted average coupon	8.00%	8.00%
Weighted average years to maturity	7 years 1 month 6 days	8 years 1 month 6 days

Number of loans held-for-investment as of period-end.

No definition available.

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- Definition

Threshold period delinquent for financing receivable to place on nonaccrual status, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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- Definition

Reflects the cumulative amount of premiums over or discounts from face amounts of loans held-for-investment that are being amortized into income as an adjustment to yield.

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

Reflects the cumulative amount of unamortized costs incurred to originate loans held-for-investment that are deferred and are being amortized into income as an adjustment to yield.

+ References

No definition available.

+ Details

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- Definition

The amount of unfunded commitments for which the entity is obligated, to loans held-for-investment.

+ References

No definition available.

+ Details

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- Definition

Weighted average coupon rate of all loans held-for-investment as of period-end.

+ References

No definition available.

+ Details

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- Definition

Weighted average years to maturity of all loans held-for-investment as of period-end.

+ References

No definition available.

+ Details

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- Definition

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.

+ References

No definition available.

+ Details

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- Definition

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

+ References

+ Details

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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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=118952595&loc=d3e4428-111522

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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