Earnings Per Common Share - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Earnings Per Share [Abstract]
Anti-dilutive common stock options and warrants (in shares)	6,200,000	6,600,000
Earnings Per Share Reconciliation [Abstract]
Net income	$ 30,341us-gaap_NetIncomeLoss	$ 33,835us-gaap_NetIncomeLoss
Basic weighted average number of common shares outstanding (in shares)	232,338,775	200,128,384
Plus: Common stock equivalents (in shares)	3,146	0
Diluted weighted average number of common shares outstanding (in shares)	232,341,921	200,128,384
Earnings Per Share, Basic and Diluted [Abstract]
Basic (in usd per share)	$ 0.13us-gaap_EarningsPerShareBasic	$ 0.17us-gaap_EarningsPerShareBasic
Diluted (in usd per share)	$ 0.13us-gaap_EarningsPerShareDiluted	$ 0.17us-gaap_EarningsPerShareDiluted

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

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