Debt and Preferred Equity Investments - Investment In Financing Receivable (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Financing Receivable, Credit Quality Indicator [Line Items]
Carrying value	$ 1,072,711	$ 1,076,542
2021	62,240
2020	270,254
2019	303,726
Prior	436,491
1 - Low Risk Assets - Low probability of loss
Financing Receivable, Credit Quality Indicator [Line Items]
Carrying value	682,565	695,035
2021	62,240
2020	270,254
2019	57,148
Prior	292,923
2 - Watch List Assets - Higher potential for loss
Financing Receivable, Credit Quality Indicator [Line Items]
Carrying value	373,788	365,167
2021	0
2020	0
2019	246,578
Prior	127,210
3 - High Risk Assets - Loss more likely than not
Financing Receivable, Credit Quality Indicator [Line Items]
Carrying value	16,358	$ 16,340
2021	0
2020	0
2019	0
Prior	$ 16,358