Commitments and Contingencies - Additional Information (Detail) $ in Millions	12 Months Ended					24 Months Ended
	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2009 interest_plan	Dec. 31, 2008 interest_plan	Dec. 31, 2009 interest_plan
Commitments and Contingencies Disclosure [Abstract]
Rent expense	$ 3.6	$ 1.3	$ 2.4
Number of carried interest plans | interest_plan				1	1	2
Carried interest rate (as a percent)						15.00%
Plan investment deployed amount approximately	$ 78.0	$ 19.5	$ 23.5