| **CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY AND COMPREHENSIVE INCOME (LOSS) (USD $)In Thousands, unless otherwise specified** | Common Stock | Additional Paid-In Capital | Accumulated Deficit | Accumulated Other Comprehensive Income (Loss) | Treasury Stock | Total     |
|-------------------------------------------------------------------------------------------------------------------------------------|--------------|----------------------------|---------------------|-----------------------------------------------|----------------|-----------|
| Balance at Dec. 31, 2008                                                                                                            | $ 40         | $ 422,085                  | $ (298,718)         | $ (1,297)                                     | $ (2,741)      | $ 119,369 |
| Balance (Shares) at Dec. 31, 2008                                                                                                   | 30,807       |                       |                |                                          | (200)          |      |
| **Comprehensive income (loss):**                                                                                                    |         |                       |                |                                          |           |      |
| Net income (loss)                                                                                                                   |         |                       | (30,612)            |                                          |           | (30,612)  |
| Net unrealized gain on marketable and auction rate securities                                                                       |         |                       |                | 990                                           |           | 990       |
| Total comprehensive income (loss):                                                                                                  |         |                       |                |                                          |           | (29,622)  |
| Compensation expenses for share-based payment arrangements                                                                          |         | 12,986                     |                |                                          |           | 12,986    |
| Issuance of restricted stock, net of forfeitures (in shares)                                                                        | 266          |                       |                |                                          |           |      |
| Sale of common stock under employee stock purchase plans and exercise of stock options (in shares)                                  | 1,069        |                       |                |                                          |           |      |
| Sale of common stock under employee stock purchase plans and exercise of stock options                                              | 2            | 4,872                      |                |                                          |           | 4,874     |
| Balance at Dec. 31, 2009                                                                                                            | 42           | 439,943                    | (329,330)           | (307)                                         | (2,741)        | 107,607   |
| Balance (Shares) at Dec. 31, 2009                                                                                                   | 32,142       |                       |                |                                          | (200)          |      |
| **Comprehensive income (loss):**                                                                                                    |         |                       |                |                                          |           |      |
| Net income (loss)                                                                                                                   |         |                       | (69,725)            |                                          |           | (69,725)  |
| Net unrealized gain on marketable and auction rate securities                                                                       |         |                       |                | 15                                            |           | 15        |
| Total comprehensive income (loss):                                                                                                  |         |                       |                |                                          |           | (69,710)  |
| Compensation expenses for share-based payment arrangements                                                                          |         | 9,515                      |                |                                          |           | 9,515     |
| Issuance of restricted stock, net of forfeitures (in shares)                                                                        | 173          |                       |                |                                          |           |      |
| Sale of common stock under employee stock purchase plans and exercise of stock options (in shares)                                  | 1,011        |                       |                |                                          |           |      |
| Sale of common stock under employee stock purchase plans and exercise of stock options                                              | 1            | 3,895                      |                |                                          |           | 3,896     |
| Balance at Dec. 31, 2010                                                                                                            | 43           | 453,353                    | (399,055)           | (292)                                         | (2,741)        | 51,308    |
| Balance (Shares) at Dec. 31, 2010                                                                                                   | 33,326       |                       |                |                                          | (200)          |      |
| **Comprehensive income (loss):**                                                                                                    |         |                       |                |                                          |           |      |
| Net income (loss)                                                                                                                   |         |                       | 10,381              |                                          |           | 10,381    |
| Net unrealized gain on auction rate securities                                                                                      |         |                       |                | 24                                            |           | 24        |
| Total comprehensive income (loss):                                                                                                  |         |                       |                |                                          |           | 10,405    |
| Compensation expenses for share-based payment arrangements                                                                          |         | 6,362                      |                |                                          |           | 6,362     |
| Forefeitures of restricted stock (in shares)                                                                                        | (38)         |                       |                |                                          |           |      |
| Sale of common stock under employee stock purchase plans and exercise of stock options (in shares)                                  | 758          |                       |                |                                          |           |      |
| Sale of common stock under employee stock purchase plans and exercise of stock options                                              | 1            | 3,725                      |                |                                          |           | 3,726     |
| Balance at Dec. 31, 2011                                                                                                            | $ 44         | $ 463,440                  | $ (388,674)         | $ (268)                                       | $ (2,741)      | $ 71,801  |
| Balance (Shares) at Dec. 31, 2011                                                                                                   | 34,046       |                       |                |                                          | (200)          |      |

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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
This element represents the amount of recognized equity-based compensation during the period, that is, the amount recognized as expense in the income statement (or as asset if compensation is capitalized). Alternate captions include the words "stock-based compensation".
+ 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 profit or loss for the period, net of income taxes, which is attributable to the parent.
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Gross appreciation or the gross loss in value of the total unsold securities. While for technical reasons this element has no balance attribute, the default assumption is a credit balance consistent with its label.
+ References
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Appreciation or loss in value (before reclassification adjustment) of the total of unsold securities during the period being reported on, net of tax. Reclassification adjustments include: (1) the unrealized holding gain (loss), net of tax, at the date of the transfer for a debt security from the held-to-maturity category transferred into the available-for-sale category. Also includes the unrealized gain (loss) at the date of transfer for a debt security from the available-for-sale category transferred into the held-to-maturity category; (2) the unrealized gains (losses) realized upon the sale of securities, after tax; and (3) the unrealized gains (losses) realized upon the write-down of securities, 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 related to Restricted Stock Award forfeited during the period.
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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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