Equity Investments in Unconsolidated Subsidiaries - Additional Information (Detail) - CT Opportunity Partners I, LP [Member] - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Jan. 31, 2011
Schedule of Equity Method Investments [Line Items]
Carried interest revenue, percentage of fund's profit	17.70%
Preferred return	9.00%
Return of capital to partners	100.00%
Carried interest revenue	$ 7.4
Promote income recognized	$ 5.7
Percentage of carried interest distributions pool for employees		45.00%
Percentage of pool vested	68.00%
Description of incentive management fee grants to employees vesting schedule	Approximately 68% of the pool is two-thirds vested as of June 30, 2015, with the remainder contingent on continued employment with an affiliate of our Manager and upon our receipt of promote distributions from CTOPI. The remaining 32% of the pool is fully vested as a result of an acceleration event. During the six months ended June 30, 2015, we accrued $2.5 million under the CTOPI incentive plan, which amount was recognized as a component of general and administrative expenses in our consolidated statement of operations.
Accrued expenses for incentive plan	$ 2.5
Acceleration Event [Member]
Schedule of Equity Method Investments [Line Items]
Fully vested pool, percentage	32.00%