Basic and Diluted Net Income or Loss Per Share Calculation (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Earnings Per Share Disclosure [Line Items]
Net income (loss) available to common stockholders	$ 107	$ (1,500)
Weighted average shares outstanding, basic	50,336	50,124
Weighted average shares outstanding, diluted	51,033	50,124
Net income (loss) per share, basic and diluted	$ 0.00	$ (0.03)
Anti-dilutive securities excluded from diluted net income (loss) per share calculation for stock-based compensation plans	7,218	6,688

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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-Name Accounting Standards Codification

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-Publisher FASB

-Name Accounting Standards Codification

-Glossary Diluted Earnings Per Share

-URI http://asc.fasb.org/extlink&oid=6510752

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-Name Accounting Standards Codification

-Topic 260

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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

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+ Details