Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Jan. 01, 2021
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Cash, FDIC Insured Amount	$ 250,000
Non-controlling interests	37,636,000	$ 35,286,000
Retained earnings	664,700,000	526,205,000	$ 78,251,000
Public Offering
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Offering cost classified as Other Asset	0	16,000,000
Accrued other assets	0	16,000,000
Offering costs incurred and charged to Additional Paid in Capital	11,800,000	1,000,000.0
Accrued offering costs charged to additional paid in capital	$ 300,000	1,500,000
Retained Earnings [Member] | Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Retained earnings			$ 78,300,000
C M T G T T Mortgage R E I T L L C | Parent
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent	51.00%
Stockholders equity of minority interest entity	$ 76,800,000	72,000,000.0
C M T G T T Mortgage R E I T L L C | Noncontrolling Interest [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	49.00%
Non-controlling interests	$ 37,600,000	$ 35,300,000
Product Concentration Risk | Floating Rate [Member] | Secured Term Loan | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Concentration risk, percentage	0.05%