Other Expenses - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Management fee - percent of outstanding equity balance			1.50%
Incentive fee computation-percent of the product per agreement			20.00%
Incentive fee computation-percent of outstanding Equity per annum			7.00%
Management fees description			Manager is entitled to an incentive fee in an amount equal to the product of (i) 20% and (ii) the excess of (a) our Core Earnings (as defined in our management agreement) for the previous 12-month period over (b) an amount equal to 7.00% per annum multiplied by our outstanding Equity, provided that our Core Earnings over the prior three-year period is greater than zero. Core Earnings, as defined in our management agreement, is generally equal to our net income (loss) prepared in accordance with GAAP, excluding (i) certain non-cash items (ii) the net income (loss) related to our legacy portfolio and (iii) incentive management fees.
Management fees	$ 13,701,000	$ 13,813,000	$ 43,161,000	$ 28,535,000
Manager [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Management fees	9,500,000	9,400,000	28,400,000	22,900,000
Incentive fees payable	4,200,000	$ 4,500,000	14,800,000	$ 5,700,000
Accrued management and incentive fees payable	$ 13,700,000		$ 13,700,000		$ 14,400,000
Incentive Awards Plan [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Percentage of the dividends paid to common equity holders created employee pool	6.75%		6.75%
Percentage of pool vested			50.00%
Vested pool, percentage			75.00%
Fully vested pool, percentage	27.00%		27.00%
Percentage of pool vesting upon receipt of dividends	23.00%		23.00%
Description of incentive management fee awards to employees vesting schedule			Approximately 50% of the pool was 75% vested as of September 30, 2016, with the remainder contingent on continued employment with an affiliate of our Manager and our receipt of distributions from CT Legacy Partners. Of the remaining 50% of the pool, 27% is fully vested as a result of an acceleration event, and 23% vest only upon our receipt of distributions from CT Legacy Partners.
Accrued payables, awards	$ 114,000		$ 114,000		$ 1,300,000