Fair Value - Summary of Assets Carried at Fair Value on a Nonrecurring Basis (Details) - USD ($) $ in Thousands		Jun. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans and preferred equity held for investment, net	[1]	$ 2,242,574	$ 2,576,332
Real estate, net		823,531	1,484,796
Assets held for sale		760,290	189,470
Fair value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans and preferred equity held for investment, net		2,242,574	104,797
Loans held for sale		104,900	5,016
Real estate, net		0	448,690
Assets held for sale		154,226	134,966
Investments in unconsolidated ventures - PE Investments		0	211,024
Deferred leasing costs and intangible assets, net		0	42,122
Fair value, measurements, nonrecurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans and preferred equity held for investment, net		0	0
Loans held for sale		0	0
Real estate, net		0	0
Assets held for sale		0	0
Investments in unconsolidated ventures - PE Investments		0	0
Deferred leasing costs and intangible assets, net		0	0
Fair value, measurements, nonrecurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans and preferred equity held for investment, net		0	0
Loans held for sale		0	0
Real estate, net		0	0
Assets held for sale		0	0
Investments in unconsolidated ventures - PE Investments		0	0
Deferred leasing costs and intangible assets, net		0	0
Fair value, measurements, nonrecurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans and preferred equity held for investment, net		2,242,574	104,797
Loans held for sale		104,900	5,016
Real estate, net		0	448,690
Assets held for sale		154,226	134,966
Investments in unconsolidated ventures - PE Investments		0	211,024
Deferred leasing costs and intangible assets, net		$ 0	$ 42,122

[1] Net of $52.5 million and $272.6 million of allowance for loan losses at June 30, 2020 and December 31, 2019, respectively. See Note 3, “Loans and Preferred Equity Held for Investments, net and Loans Held for Sale” for further details.