Equity Investments in Unconsolidated Subsidiaries - Additional Information (Detail) (CT Opportunity Partners I, LP [Member], USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 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	$ 11.6
Promote income recognized	3.9
Percentage of carried interest distributions pool for employees		45.00%
Percentage of granted carried interest distributions to employees	96.00%
Percentage of grants vesting schedule	65.00%
Percentage of grants vesting upon receipt of dividends	35.00%
Description of incentive management fee grants to employees vesting schedule	(i) one-third on the date of grant; (ii) one-third on September 13, 2012; and (iii) the remainder is contingent on continued employment with an affiliate of our Manager and upon our receipt of carried interest distributions from CTOPI. Of the remaining 35% of these grants, 31% are fully vested as a result of an acceleration event, and 4% vest solely upon our receipt of carried interest distributions from CTOPI or the disposition of certain investments owned by CTOPI.
Accrued expenses for incentive plan	$ 1.8
Acceleration Event [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of grants vesting upon receipt of dividends	31.00%
Incentive Management Fees [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of grants vesting upon receipt of dividends	4.00%