Investments of Consolidated Affordable Housing Fund - Narrative (Details) - Primary Beneficiary $ in Thousands	1 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2017 affordable_housing_community	Sep. 30, 2023 USD ($) affordable_housing_community affordable_housing_unit	Dec. 31, 2018 affordable_housing_community	Dec. 31, 2016 affordable_housing_community	Dec. 31, 2015 affordable_housing_community	Dec. 31, 2022 USD ($)
Investments in and Advances to Affiliates [Line Items]
Investments of consolidated affordable housing fund, at fair value		$ 1,979,184				$ 1,761,002
Woodstar I Portfolio
Investments in and Advances to Affiliates [Line Items]
Number of affordable housing communities in portfolio | affordable_housing_community		32
Number of affordable housing units in portfolio | affordable_housing_unit		8,948
Number of affordable housing communities acquired in portfolio | affordable_housing_community				14	18
Investments of consolidated affordable housing fund, at fair value		$ 1,800,000
Debt fair value		$ 728,800
Woodstar II Portfolio
Investments in and Advances to Affiliates [Line Items]
Number of affordable housing communities in portfolio | affordable_housing_community		27
Number of affordable housing units in portfolio | affordable_housing_unit		6,109
Number of affordable housing communities acquired in portfolio | affordable_housing_community	8		19
Investments of consolidated affordable housing fund, at fair value		$ 1,400,000
Debt fair value		$ 475,600