Equity-Based Compensation - Additional Information (Detail) (USD $)	1 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended	1 Months Ended	6 Months Ended	0 Months Ended	3 Months Ended	6 Months Ended
	May 20, 2014	Oct. 07, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013 Common Class B	Oct. 01, 2013 Common Class A	Jun. 30, 2014 Common Class A	Nov. 15, 2012 Board Of Managers Options Common Class B	Jun. 30, 2014 Restricted Stock Units (RSUs)	Jun. 30, 2014 Restricted Stock Units (RSUs)
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
Estimated value of withheld shares	$ 818,000				$ 818,000				$ 30,519,000
Income tax benefit realized upon issuance of underlying shares					125,000
Equity-based compensation			$ 74,000	$ 321,000	$ 332,000	$ 701,000					$ 74,000	$ 332,000
Options granted								787,500		31,500
Stock split							25
Additional shares available			1,679,167		1,679,167