Summary of Equity-Based Compensation Activity (Detail)	9 Months Ended
	Sep. 30, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Balance as of January 1, 2014	241,854
Granted	0
Exercised	0
Forfeited	(9,550)
Delivered and exchanged for shares of Class A common stock	(77,452)
Cancelled	(30,519)
Balance as of September 30, 2014	124,333
Vested	0
Unvested	124,333
Balance as of January 1, 2014	787,500
Options granted	0
Exercised	(15,000)
Balance as of September 30, 2014	772,500
Vested	772,500