Financial Guarantee Liability - Narrative (Details) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023 USD ($) loan	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) loan	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($) loan
Guarantor Obligations
Outstanding loan balances	$ 28,600,000		$ 28,600,000		$ 27,600,000
Maximum loss potential	8,700,000		8,700,000		8,400,000
Provision (reversal) for expected credit losses	(800)	$ 700	3,405	$ 600	1,740
Financial guarantee liability, settlment loss					1,200
Financial guarantee liability, settlement loss, write off					600
Delinquent
Guarantor Obligations
Outstanding loan balances	7,300		7,300		7,300
Maximum loss potential	$ 2,400		$ 2,400		$ 2,400
Number of loans | loan	1		1		1
Liquidation value of loans outstanding	$ 7,500		$ 7,500		$ 4,200
Potential loss on liquidation of loan			$ 500		1,100
Foreclosure
Guarantor Obligations
Outstanding loan balances					22,800
Maximum loss potential					$ 7,600
Number of loans | loan					1
Liquidation value of loans outstanding					$ 20,000
Potential loss on liquidation of loan					$ 1,500
Fannie Mae DUS or Freddie TAH Loans | Maximum
Guarantor Obligations
Percentage of contingent liability of actual losses incurred on outstanding loans			33.00%