COMMERCIAL MORTGAGE LOANS HELD-FOR-INVESTMENT Loan Portfolio Activity (Details) - USD ($)	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at December 31, 2017	$ 0
Purchases, net	410,901,286	$ 0
Proceeds from principal repayments	(201,392,408)	0
Balance at December 31, 2018	555,172,891	0
Commercial Real Estate Portfolio Segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at December 31, 2017	0
Purchases, net	756,565,299
Proceeds from principal repayments	(201,392,408)
Balance at December 31, 2018	$ 555,172,891	$ 0

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.

No definition available.

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- Definition

Net amount of the investment in a contractual right to receive money on demand or on fixed or determinable dates that is recognized as an asset in the creditor's statement of financial position. Examples include, but are not limited to, credit card receivables, notes receivable and receivables relating to lessor's rights to payments from leases other than operating leases that have been recorded as assets. Excludes trade accounts receivable with contractual maturity of one year or less and arose from the sale of goods or services.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.3)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

The cash outflow associated with purchasing loans held for investment purposes during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3213-108585

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- Definition

The cash inflow from repayments of the balance excluding interest (principal) on loans receivable and leases held for investment purposes.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3179-108585

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