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		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Net Income (Loss)	$ 16,276	$ (3,703)	$ 36,846	$ 25,034
Noncontrolling interests	(651)	3,054	(770)	3,436
Net Income (Loss) Attributable to Common Stockholders	$ 15,625	$ (649)	$ 36,076	$ 28,470
Shares:
Basic: Weighted-average number of shares outstanding (in shares)	7,676	8,775	8,062	8,876
Plus: Incremental shares from assumed conversion of dilutive instruments (in shares)	178	0	161	163
Diluted: Weighted-average number of shares outstanding (in shares)	7,854	8,775	8,223	9,039
Earnings (Loss) per share—Basic (in $ per share)	$ 2.04	$ (0.07)	$ 4.47	$ 3.21
Earnings (Loss) per Share—Diluted (in $ per share)	$ 1.99	$ (0.07)	$ 4.39	$ 3.15