| **CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY AND COMPREHENSIVE INCOME (LOSS) (Unaudited) (USD $)In Thousands** | Total     | Common Stock | Additional Paid-In Capital | Accumulated Deficit | Accumulated Other Comprehensive Income (Loss) | Treasury Stock |
|---------------------------------------------------------------------------------------------------------------------|-----------|--------------|----------------------------|---------------------|-----------------------------------------------|----------------|
| Balance, beginning at Dec. 31, 2009                                                                                 | $ 107,607 | $ 42         | $ 439,943                  | $ (329,330)         | $ (307)                                       | $ (2,741)      |
| Balance, beginning (in shares) at Dec. 31, 2009                                                                     |      | 32,142       |                       |                |                                          | (200)          |
| **Comprehensive income (loss):**                                                                                    |      |         |                       |                |                                          |           |
| Net income (loss)                                                                                                   | (50,925)  |         |                       | (50,925)            |                                          |           |
| Net change in unrealized loss on securities                                                                         | 15        |         |                       |                | 15                                            |           |
| Total comprehensive income (loss)                                                                                   | (50,910)  |         |                       |                |                                          |           |
| Compensation expenses for share-based payment arrangements                                                          | 7,726     |         | 7,726                      |                |                                          |           |
| Issuance of restricted stock, net of forfeitures (in shares)                                                        |      | 187          |                       |                |                                          |           |
| Sale of common stock under employee stock purchase plans and exercise of stock options (in shares)                  |      | 776          |                       |                |                                          |           |
| Sale of common stock under employee stock purchase plans and exercise of stock options                              | 2,987     | 1            | 2,986                      |                |                                          |           |
| Balance, ending at Sep. 30, 2010                                                                                    | 67,410    | 43           | 450,655                    | (380,255)           | (292)                                         | (2,741)        |
| Balance, ending (in shares) at Sep. 30, 2010                                                                        |      | 33,105       |                       |                |                                          | (200)          |
| Balance, beginning at Dec. 31, 2010                                                                                 | 51,308    | 43           | 453,353                    | (399,055)           | (292)                                         | (2,741)        |
| Balance, beginning (in shares) at Dec. 31, 2010                                                                     |      | 33,326       |                       |                |                                          | (200)          |
| **Comprehensive income (loss):**                                                                                    |      |         |                       |                |                                          |           |
| Net income (loss)                                                                                                   | 21,127    |         |                       | 21,127              |                                          |           |
| Net change in unrealized loss on securities                                                                         | 16        |         |                       |                | 16                                            |           |
| Total comprehensive income (loss)                                                                                   | 21,143    |         |                       |                |                                          |           |
| Compensation expenses for share-based payment arrangements                                                          | 4,695     |         | 4,695                      |                |                                          |           |
| Issuance of restricted stock, net of forfeitures (in shares)                                                        |      | (34)         |                       |                |                                          |           |
| Sale of common stock under employee stock purchase plans and exercise of stock options (in shares)                  |      | 665          |                       |                |                                          |           |
| Sale of common stock under employee stock purchase plans and exercise of stock options                              | 3,234     | 1            | 3,233                      |                |                                          |           |
| Balance, ending at Sep. 30, 2011                                                                                    | $ 80,380  | $ 44         | $ 461,281                  | $ (377,928)         | $ (276)                                       | $ (2,741)      |
| Balance, ending (in shares) at Sep. 30, 2011                                                                        |      | 33,957       |                       |                |                                          | (200)          |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
This element represents the amount of recognized share-based compensation during the period, that is, the amount recognized as expense in the income statement (or as asset if compensation is capitalized).
+ References
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the reporting entity. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, but excludes any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent.
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The portion of consolidated profit or loss for the period, net of income taxes, which is attributable to the parent. If the entity does not present consolidated financial statements, the amount of profit or loss for the period, net of income taxes.
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Gross appreciation or the gross loss in value of the total unsold securities at the end of an accounting period, after tax.
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| - Definition
Number of shares of stock issued as of the balance sheet date, including shares that had been issued and were previously outstanding but which are now held in the treasury.
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Total of all Stockholders' Equity (deficit) items, net of receivables from officers, directors owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Number of shares issued during the period as a result of an employee stock purchase plan.
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Number of shares issued during the period related to Restricted Stock Awards, net of any shares forfeited.
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Aggregate change in value for stock issued during the period as a result of employee stock purchase plan.
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