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	6 Months Ended
Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Earnings Per Share [Abstract]
Net Income	$ 8,700	$ 9,012	$ 20,570	$ 28,737
Noncontrolling interests	(612)	765	(119)	382
Net Income Attributable to Common Stockholders	$ 8,088	$ 9,777	$ 20,451	$ 29,119
Shares:
Basic: Weighted-average number of shares outstanding (in shares)	8,170	8,889	8,257	8,927
Plus: Incremental shares from assumed conversion of dilutive instruments (in shares)	144	148	153	167
Diluted: Weighted-average number of shares outstanding (in shares)	8,314	9,037	8,410	9,094
Earnings per share—Basic (in $ per share)	$ 0.99	$ 1.10	$ 2.48	$ 3.26
Earnings per Share—Diluted (in $ per share)	$ 0.97	$ 1.08	$ 2.43	$ 3.20

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Amount after tax of income (loss) from continuing operations attributable to the noncontrolling interest.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

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Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

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