Income Per Share - Weighted Average Number of Common Shares Outstanding (Detail) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Earnings Per Share [Abstract]
Weighted average shares outstanding - basic	52,427	48,715
Effect of dilutive stock-based compensation	589	608
Effect of convertible notes	7,702	814
Effect of common stock warrants	6,002
Weighted average shares outstanding - diluted	66,720	50,137

Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of call options and warrants using the treasury stock method.

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+ Details

- 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.

+ References+ Details

- 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

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-URI http://asc.fasb.org/extlink&oid=6528421

+ Details