Earnings Per Common Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share Reconciliation
Net income available to common shareholders	$ 36,966	$ 41,045	$ 129,532	$ 112,665
Basic weighted average number of common shares outstanding (in shares)	264,058,174	254,473,994	263,938,786	254,310,769
Plus: Common stock equivalents (in shares)	878,046	466,313	816,059	387,824
Diluted weighted average number of common shares outstanding (in shares)	264,936,220	254,940,307	264,754,845	254,698,593
Earnings per common share:
Basic (usd per share)	$ 0.14	$ 0.16	$ 0.49	$ 0.44
Diluted (usd per share)	$ 0.14	$ 0.16	$ 0.49	$ 0.44
Anti-dilutive common stock options and warrants (in shares)	3,300,000	4,600,000	3,300,000	4,600,000

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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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 deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.

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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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