Equity-Based Compensation Plan - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended								12 Months Ended				1 Months Ended	12 Months Ended	1 Months Ended		12 Months Ended		1 Months Ended		12 Months Ended
	Oct. 31, 2013	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Board Of Managers Options	Oct. 31, 2013 Common Class A	Dec. 31, 2013 Common Class B	Oct. 31, 2013 Restricted stock units	Jul. 31, 2013 Restricted stock units	Dec. 31, 2013 Restricted stock units	Dec. 31, 2013 Restricted stock units 2013 Stock Incentive Plan	Oct. 31, 2013 Restricted stock units Employees	Oct. 31, 2013 Restricted stock units Directors	Dec. 31, 2013 Restricted stock units Directors
Restricted stock units granted																107,971				115,699	18,184
Restricted stock units granted, value per unit														$ 22.00		$ 18.96				$ 22.00	$ 22.00
Non-cash compensation expense										$ 701,000	$ 1,089,000							$ 2,047,000				$ 247,000
Vesting Period																				3 years	1 year
Unrecognized compensation cost																		2,512,000
Options outstanding, remaining contractual term																		2 years 6 months
Tax Benefit related to the restricted stock units granted		1,111,000	702,000	577,000	454,000	398,000	636,000	638,000	466,000	2,844,000	2,138,000	2,172,000					345,000
Additional shares available to grant under plan																			1,336,439
Options granted	787,500												31,500
Stock split	25
Options outstanding, Exercise price		$ 3.60								$ 3.60
Options outstanding, remaining contractual term										8 years 10 months 24 days
Weighted average grant-date fair value of common unit options															$ 56.83
Total fair value of options										$ 895,000	$ 895,000