Loans - Secured Loans by Property Type (Parenthetical) (Details)	1 Months Ended	9 Months Ended	12 Months Ended
	Jun. 30, 2020 MortgageLoan	Sep. 30, 2021 USD ($) MortgageLoan	Dec. 31, 2020 USD ($) MortgageLoan	Jun. 30, 2021 USD ($)
Loans Details [Line Items]
Number of secured loans | MortgageLoan	2	33	33
Secured loans, principal | $		$ 70,227,000	$ 74,080,000	$ 72,548,000
Single Family Property-Owner Occupied [Member]
Loans Details [Line Items]
Number of secured loans | MortgageLoan		4	8
Secured loans, principal | $		$ 1,793,000	$ 3,344,000
Single Family Property-NonOwner Occupied [Member]
Loans Details [Line Items]
Number of secured loans | MortgageLoan		12	11
Secured loans, principal | $		$ 11,699,000	$ 13,254,000