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Multifamily Loans - Geographic Concentration of Multifamily Loans (Details) - Multifamily loans	12 Months Ended
	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk percentage	100.00%
California
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk percentage	11.00%
Texas
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk percentage	9.00%
Arizona
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk percentage	8.00%
Georgia
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk percentage	6.00%
Other states (none greater than 5%)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk percentage	66.00%

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- Definition

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+ References

No definition available.

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
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