Earnings Per Common Share - Computation of Basic and Diluted Earnings Per Common Share (Detail) - USD ($) $ / shares in Units, $ 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	$ 41,300	$ 40,131	$ 67,432	$ 80,474
Less: Preferred stock dividends	2,010	2,010	4,020	4,020
Net income available to common stockholders	$ 39,290	$ 38,121	$ 63,412	$ 76,454
Basic weighted average common shares outstanding	210,106,985	174,940,911	201,846,343	174,548,775
Net effect of dilutive stock options, warrants, restricted stock and convertible debt	1,568,464	1,420,929	1,425,062	1,547,420
Diluted weighted average common shares outstanding	211,675,449	176,361,840	203,271,405	176,096,195
Basic	$ 0.19	$ 0.22	$ 0.31	$ 0.44
Diluted	$ 0.19	$ 0.22	$ 0.31	$ 0.43

Amount of paid and unpaid preferred stock dividends declared with the form of settlement in cash, stock and payment-in-kind (PIK).

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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 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 sum of dilutive potential common shares or units used in the calculation of the diluted per-share or per-unit computation.

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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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