Equity Investment in Unconsolidated Subsidiary - Additional Information (Detail) - CT Opportunity Partners I, LP [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2016	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%
Promote income recognized		$ 3.2
Percentage of carried interest distributions pool for employees			45.00%
Description of incentive management fee grants to employees vesting schedule	During the year ended December 31, 2016, we recognized $3.2 million of promote income from CTOPI in respect of our carried interest and recorded such amounts as income in our consolidated statement of operations.
CTOPI Incentive Plan [Member]
Schedule of Equity Method Investments [Line Items]
Recognized expenses for incentive plan		$ 1.6