Earnings per Share - Schedule of Computation of Basic and Diluted EPS (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	0 Months Ended	3 Months Ended	9 Months Ended
Aug. 13, 2014	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]
Net Income		$ 36,995	$ 21,302	$ 78,554	$ 50,270
Noncontrolling interests		345	(213)	267	164
Net Income Attributable to Common Stockholders		$ 37,340	$ 21,089	$ 78,821	$ 50,434
Shares:
Basic: Weighted-average number of shares outstanding		9,096	7,995	9,115	7,879
Plus: Incremental shares from assumed conversion of dilutive instruments		183	232	207	246
Diluted: Weighted-average number of shares outstanding		9,279	8,227	9,322	8,125
Earnings per share - basic		$ 4.10	$ 2.64	$ 8.65	$ 6.40
Earnings per share - diluted		$ 4.02	$ 2.56	$ 8.46	$ 6.21
Cash dividends declared per share	$ 0.45	$ 0.45		$ 0.90

Aggregate dividends declared during the period for each share of common stock outstanding.

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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 of income (loss) from continuing operations attributable to the noncontrolling interest. Also defined as revenue less expenses and taxes from ongoing operations before extraordinary items but after deduction of those portions of income or loss from continuing operations that are allocable to noncontrolling interests.

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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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