Transactions with Related Parties - Additional Information (Detail) (USD $)	0 Months Ended			1 Months Ended	12 Months Ended			1 Months Ended			0 Months Ended
	Oct. 23, 2013	Oct. 02, 2013	May 13, 2013	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2014	Apr. 30, 2014	Jan. 31, 2014	Oct. 23, 2014	Oct. 03, 2013	Dec. 20, 2012	May 30, 2013	May 31, 2013	Jun. 20, 2014	Nov. 19, 2013	May 22, 2013	Feb. 10, 2015
Related Party Transaction [Line Items]
Class A common shares acquired by Holdings III, shares				100,000	28,275,006	25,875,000	669,047
Management Agreement expiration date					Dec. 19, 2015
Management Agreement renewal term, description					The initial term of the Management Agreement expires on December 19, 2015 and will be automatically renewed for a one-year term each anniversary thereafter unless earlier terminated.
Issuance of restricted class A common stock					490,381	700,000	36,493
Common stock value				$ 583,000	$ 583,000	$ 295,000
Joint venture agreement date					May 13, 2013
Percentage of equity interest purchased			100.00%											100.00%
Joint venture agreement end date					May 30, 2013
Charge to non-controlling interest from purchase of equity interests at fair value			193,000
Common stock, shares issued				58,269,889	58,269,889	29,501,651
Common stock, par value				$ 0.01	$ 0.01	$ 0.01
Convertible notes				161,853,000	161,853,000	159,524,000
Amount of loan originated		71,000,000
Purchased loan from third party	176,900,000
Proceeds from partial repayments of loans					119,400,000
Net Book Value Of Loans					53,800,000
Minimum [Member]
Related Party Transaction [Line Items]
Investment threshold amount				150,000,000	150,000,000
Second Amended and Restated Management Agreement [Member] | Minimum [Member]
Related Party Transaction [Line Items]
Investment threshold amount				250,000,000	250,000,000
Class A Common Stock [Member]
Related Party Transaction [Line Items]
Class A common shares acquired by Holdings III, shares				100,000	28,275,000			9,200,000	9,200,000	9,775,000
Common stock, shares issued															25,875,000
CT Legacy Portfolio [Member]
Related Party Transaction [Line Items]
Aggregate principal balance of loans																35,000,000
Aggregate book value of loans																27,000,000
Manager [Member]
Related Party Transaction [Line Items]
Issuance of restricted class A common stock											337,941	339,431
Common stock value											9,400,000	8,500,000
Vesting period of restricted class A common stock												3 years
Non-cash expense					3,800	767,000,000
Affiliate of Manager [Member]
Related Party Transaction [Line Items]
Accrued management fees payable				6,300,000	6,300,000
Management fees paid to Manager					15,700,000
Percentage of equity interest purchased			83.30%
Convertible notes																	188,000
Modification fee	2,300,000
Affiliate of Manager [Member] | Class A Common Stock [Member]
Related Party Transaction [Line Items]
Common stock value																		1,000,000
Common stock, shares issued																		1,960,784
Common stock, par value																		$ 25.50
Affiliate of Manager [Member] | Subsequent Events [Member] | Class A Common Stock [Member]
Related Party Transaction [Line Items]
Common stock, shares outstanding percentage																			5.40%
Affiliate of our Manager [Member]
Related Party Transaction [Line Items]
Preferred distributions payable to affiliate of our Manager					115,000
Payments of preferred distributions to affiliate of our Manager					2,100,000
Preferred distributions payable to affiliate of our Manager				151,000	151,000
Administrative services fees incurred					80,000	0
Affiliate of our Manager [Member] | Third-Party Service Provider [Member]
Related Party Transaction [Line Items]
Acquired service provider, date					Aug. 06, 2014
Administrative services fees incurred					96,000	0
Affiliate of our Manager [Member] | CT CDO I [Member]
Related Party Transaction [Line Items]
Special servicing fees					139,000	847,000
Special servicing fees payable				522,000	522,000	847,000
Affiliate of our Manager [Member] | Equity Capital Markets Data Services [Member]
Related Party Transaction [Line Items]
Service fees paid to third-party service provider					26,000	9,000
Blackstone [Member]
Related Party Transaction [Line Items]
Percentage of equity interest purchased			16.70%
W.R. Berkley Corporation [Member]
Related Party Transaction [Line Items]
Aggregate amount of offering as stated in letter agreement, threshold				$ 30,000,000	$ 30,000,000
Sale to Holdings III [Member]
Related Party Transaction [Line Items]
Class A common shares acquired by Holdings III, price per share													$ 20.00
Class A common shares acquired by Holdings III, shares													500,000