Equity-Based Compensation - Additional Information (Detail) (USD $)	0 Months Ended		3 Months Ended	9 Months Ended		0 Months Ended		9 Months Ended	0 Months Ended
	May 20, 2014	Oct. 07, 2013	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2013	Oct. 07, 2013 Common Class B	Oct. 07, 2013 Common Class A	Sep. 30, 2014 Common Class A	Nov. 15, 2012 Board Of Managers Options Common Class B	May 20, 2014 Restricted Stock Units (RSUs)	May 31, 2014 Restricted Stock Units (RSUs) Common Class A
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock units granted		107,971
Shares withheld and cancelled to cover employees statuary income tax requirements				30,519				30,519		30,519	30,519
Estimated value of withheld shares	$ 818,000			$ 818,000
Income tax benefit realized upon issuance of underlying shares		125,000		179,000
Equity-based compensation			$ 200,000	$ 532,000	$ 701,000
Options granted				0			787,500		31,500
Stock split						25
Additional shares available			1,679,167	1,679,167