Net Income Per Class A Share - Schedule of Net Income and Number of Class A Shares Used in the Calculation of Basic and Diluted Income Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Denominator:
Basic weighted average Class A shares outstanding (in shares)	57,506,195
Denominator:
Basic weighted average Class A shares outstanding (in shares)	57,506,195
Weighted average shares for diluted net income per Class A share (in shares)	57,784,240
Class A Shares
Numerator:
Net income attributable to Class A shares	$ 11,348	$ 0
Denominator:
Basic weighted average Class A shares outstanding (in shares)	57,506,195
Basic net income per Class A share	$ 0.20
Numerator:
Net income attributable to Class A shares	$ 11,348	$ 0
Denominator:
Basic weighted average Class A shares outstanding (in shares)	57,506,195
Effect of dilutive shares for diluted net income per Class A share (in shares)	278,045
Weighted average shares for diluted net income per Class A share (in shares)	57,784,240
Diluted net income per Class A share	$ 0.20