Loans and Preferred Equity Held for Investment, net - Schedule of Assets Held for Sale (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Long Lived Assets Held-for-sale [Line Items]
Loans and preferred equity held for investment, net	$ 2,103,414	$ 2,576,332
Assets held for sale	203,466	189,470
Held-for-sale
Long Lived Assets Held-for-sale [Line Items]
Loans and preferred equity held for investment, net	0	5,016
Assets held for sale	$ 0	$ 5,016