Earnings per Share - Schedule of Computation of Basic and Diluted Earnings per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Earnings Per Share [Abstract]
Net Income	$ 11,870	$ 19,725
Noncontrolling interests	493	(383)
Net Income Attributable to Common Stockholders	$ 12,363	$ 19,342
Shares:
Basic: Weighted-average number of shares outstanding (in shares)	8,344	8,964
Plus: Incremental shares from assumed conversion of dilutive instruments (in shares)	162	187
Diluted: Weighted-average number of shares outstanding (in shares)	8,506	9,151
Earnings per share—Basic (in $ per share)	$ 1.48	$ 2.16
Earnings per Share—Diluted (in $ per share)	$ 1.45	$ 2.11