Related Party Transactions - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Related Party Transaction [Line Items]
Management agreement expiration date			Aug. 25, 2025
Annual base management fee percentage			1.50%
Base management fee payable to affiliate	$ 9,843,000		$ 9,843,000		$ 9,983,000
Management fee, description			Effective October 1, 2015, the Manager earns a base management fee in an amount equal to 1.50% per annum of Stockholders’ Equity. Management fees are reduced by our pro rata share of any management fees and incentive fees (if incentive fees are not incurred by us) paid to the Manager by CMTG/TT. Management fees are paid quarterly, in arrears. Management fees of $9.8 million and $10.0 million were accrued and were included in management fee payable – affiliate, in the consolidated balance sheets at June 30, 2022 and December 31, 2021. Subsequent to June 30, 2022, we amended and restated our Management Agreement primarily to provide for reimbursement of allocable costs, including compensation, of the Manager’s non-investment professionals, to provide for automatic one-year renewals of the agreement following its original expiration date, unless it is otherwise terminated by our board of directors, and to remove historical provisions that are no longer relevant to our business and certain reporting requirements that are not customary for a public company.
Incentive fee rate			20.00%
Minimum percentage of incentive fee to be paid in return on stockholders’ equity			7.00%
Incentive fees, description			The Manager is entitled to an incentive fee equal to 20% of the excess of our Core Earnings on a rolling four-quarter basis, as defined in the Management Agreement, over a 7.00% return on Stockholders’ Equity, as defined in the Management Agreement of the Company. Incentive fees are reduced by our pro rata share of any incentive fees paid to the Manager by CMTG/TT.
Incentive fee payable to affiliate	0		$ 0		0
Termination fee, description			If we elect to terminate the Management Agreement, we are required to pay the Manager a termination fee equal to three times the sum of the average total annual amount of management fees and the average annual incentive fee paid by us over the prior two years.
Outstanding principal balance	81,800,000		$ 81,800,000		$ 54,000,000.0
Loan commitment	$ 141,100,000		$ 141,100,000
Affiliate Shareholder
Related Party Transaction [Line Items]
Common Stock Outstanding	10.80%		10.80%
Reimbursements
Related Party Transaction [Line Items]
General and administrative expense	$ 0	$ 0	$ 100,000	$ 0
CMTG/TT
Related Party Transaction [Line Items]
Incentive fee rate			3.33%
Minimum percentage of incentive fee to be paid in return on stockholders’ equity			7.00%