Loss Per Share - Schedule of Loss Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Earnings Per Share [Abstract]
Basic loss per share, Net Loss	$ (40,360)	$ (45,134)
Diluted loss per share, Net Loss	$ (40,360)	$ (45,134)
Basic loss per share, Shares	82,768	82,423
Effect of dilutive incentive-based awards, Shares
Diluted loss per share, Shares	82,768	82,423
Basic loss per share, Per Share Amount	$ (0.49)	$ (0.55)
Diluted loss per share, Per Share Amount	$ (0.49)	$ (0.55)

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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+ Details

- Definition

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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- Definition

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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- Definition

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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- Definition

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.

+ References

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Reference 7: http://www.xbrl.org/2003/role/presentationRef

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-Glossary Weighted-Average Number of Common Shares Outstanding

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+ Details