Earnings Per Share - Schedule of Calculation 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 common share - basic
Net Income	$ 42,769	$ 25,126
Preferred stock dividends	(2,576)	0
Dividends and undistributed earnings allocated to unvested restricted shares	(460)	(324)
Earnings Allocated to Common Shareholders - Basic	$ 39,733	$ 24,802
Weighted average common shares outstanding (in shares)	40,711	33,168
Earnings per common share - Basic (in usd per share)	$ 0.98	$ 0.75
Earnings per common share - diluted
Earnings Allocated to Common Shareholders - Basic	$ 39,733	$ 24,802
Dividends and undistributed earnings allocated to unvested restricted shares	(2)	(20)
Earnings allocated to common shareholders - diluted	$ 39,731	$ 24,782
Weighted average common shares outstanding (in shares)	40,711	33,168
Dilutive potential common shares - stock options (in shares)	54	67
Weighted average common shares outstanding - diluted (in shares)	40,765	33,235
Earnings per common share - Diluted (in usd per share)	$ 0.97	$ 0.75

Dilutive potential common shares stock options.

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Distributed and undistributed earnings reallocated to unvested restricted stock.

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The total amount of net income in the current period allocated to common shareholders under the two-class method of calculating earnings per share on a basic per share basis.

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Distributed and undistributed earnings to unvested restricted stock basic.

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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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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Net Income or Loss Available to Common Stockholders plus adjustments resulting from the assumption that dilutive convertible securities were converted, options or warrants were exercised, or that other shares were issued upon the satisfaction of certain conditions.

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Dividends paid to preferred stock holders that is redeemable solely at the option of the issuer.

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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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