Equity Based Compensation - Summary of Option Activity for Stock Options (Detail) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares, Outstanding, Beginning Balance	600,000
Shares, Granted	0	0
Shares, Exercised	(50,000)
Shares, Expired	0
Shares, Forfeited	0
Shares, Outstanding, Ending Balance	550,000		600,000
Shares, Exercisable	550,000
Shares, Expected to vest	0
Weighted Average Exercise Price, Outstanding, Beginning Balance	$ 8.65
Weighted Average Exercise Price, Granted	0
Weighted Average Exercise Price, Exercised	8.38
Weighted Average Exercise Price, Expired	0
Weighted Average Exercise Price, Forfeited	0
Weighted Average Exercise Price, Outstanding, Ending Balance	8.67		$ 8.65
Weighted Average Exercise Price, Exercisable	8.67
Weighted Average Exercise Price, Expected to vest	$ 0
Weighted Average Remaining Contractual Life (Yrs.), Outstanding	4 years 7 months 21 days		5 years 29 days
Weighted Average Remaining Contractual Life (Yrs.), Exercisable	4 years 7 months 21 days
Weighted Average Remaining Contractual Life (Yrs.), Expected to vest
Aggregate Intrinsic Value, Exercised	$ 1,026
Aggregate Intrinsic Value, Outstanding	9,828
Aggregate Intrinsic Value, Exercisable	9,828
Aggregate Intrinsic Value, Expected to vest	$ 0