Income Taxes - Additional Information (Details) - USD ($)	1 Months Ended	12 Months Ended
	Apr. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax [Line Items]
Unrecognized tax benefits, income tax liabilities accrued		$ 0	$ 0
Increase in unrecognized tax benefits reasonably possible		0
Interest for underpayment of income taxes		0	0
Penalties for underpayment of income taxes		0	0
Current portion of income tax expense		$ 300,000	$ 600,000	$ 300,000
Effective income tax rate		0.20%	0.50%	0.30%
Aggregate face value of debt securities		$ 4,524,725,000
Aggregate losses from the sales		1,051,000	$ (3,036,000)	$ 1,951,000
CRE Debt Securities
Income Tax [Line Items]
Aggregate face value of debt securities	$ 969,800,000
Proceeds from sale of debt securities, gross	$ 766,400,000
Aggregate losses from the sales		203,400,000
TRSs
Income Tax [Line Items]
Current portion of income tax expense		0	0	$ 0
Deferred tax assets		0	0
Deferred tax liabilities		$ 0	$ 0
REIT Subsidiaries
Income Tax [Line Items]
Equity interest percentage by parent		100.00%