| **Fair Value Measurements**            | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               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| **Fair Value Measurements [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              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| Fair Value Measurements                | 3. Fair Value MeasurementsOur available-for-sale investments consist of money market funds and auction rate securities and are recorded at fair value in the accompanying Consolidated Balance Sheets in accordance with ASC 320 Investments - Debt and Equity Securities. The change in the fair value of these securities is recorded as a component of other comprehensive income (loss).The following table presents our available-for-sale investments measured at fair value on a recurring basis, summarized by valuation hierarchy, as of December 31, 2011 and 2010:        Fair Value Measurements at December 31, 2011    Balance at December 31,2011  Quoted Pricesin ActiveMarkets forIdentical Assets (Level 1)  SignificantOtherObservableInputs (Level 2)  SignificantUnobservableInputs (Level 3)                          Money market funds  $64,068  $64,068  $-  $-Auction rate securities    3,332    -    -    3,332Total  $67,400  $64,068  $-  $3,332        Fair Value Measurements at December 31, 2010    Balance at December 31,2010  Quoted Pricesin ActiveMarkets forIdentical Assets (Level 1)  SignificantOtherObservableInputs (Level 2)  SignificantUnobservableInputs (Level 3)                          Money market funds  $43,958  $43,958  $-  $-Auction rate securities    3,608    -    -    3,608Total  $47,566  $43,958  $-  $3,608At December 31, 2011, we hold $3,332 in auction rate securities which are classified as Level 3. The fair value of these securities includes $2,392 of U.S. government subsidized securities collateralized by student loan obligations and $940 of investment company perpetual preferred stock. Auction rate securities are collateralized long-term instruments that were intended to provide liquidity through an auction process that resets interest rates at pre-determined intervals. We will not realize cash in respect of the principal amount of these securities until the issuer calls or restructures the security, the security reaches any scheduled maturity and is paid, or a buyer outside the auction process emerges. As of December 31, 2011, we have received all scheduled interest payments on these securities, which, in the event of auction failure, are reset according to the contractual terms in the governing instruments.The valuation of auction rate securities we hold is based on Level 3 unobservable inputs which consist of our internal analysis of (i) timing of expected future successful auctions, (ii) collateralization of underlying assets of the security and (iii) credit quality of the security. In re-evaluating the valuation of these securities as of December 31, 2011, the temporary impairment amount decreased $24 from $292 at December 31, 2010, to $268, which is reflected as a part of accumulated other comprehensive loss on our accompanying Consolidated Balance Sheets. These securities are held "available-for-sale" and the unrealized loss is included in accumulated other comprehensive loss. Due to the uncertainty related to the liquidity in the auction rate security market and therefore when individual positions may be liquidated, we have classified these auction rate securities as long-term assets on our accompanying Consolidated Balance Sheets. We continue to monitor markets for our investments and consider the impact, if any, of market conditions on the fair market value of our investments. We do not believe the carrying values of our investments are other than temporarily impaired and therefore expect the positions will eventually be liquidated without significant loss.For those of our financial instruments with significant Level 3 inputs (all auction rate securities), the following tables summarize the activities for the years ended December 31, 2011 and 2010:   Fair Value Measurements Using SignificantUnobservable Inputs(Level 3) Description 2011  2010         Balance at beginning of period $3,608  $3,792 Transfers into Level 3  -   - Total realized/unrealized gains (losses)        Included in net income (loss)  -   - Included in comprehensive income (loss) (1)  24   16 Settlements  (300 )  (200 )Balance at end of period $3,332  $3,608 (1)  Total amount of unrealized gains (losses) for the period included in other comprehensive loss attributable to the change in fair market value of related assets still held at the reporting date $-  $- The following tables summarize the amortized cost basis, the aggregate fair value and gross unrealized holding gains and losses at December 31, 2011 and 2010:   Amortized  Fair  Unrealized Holding    Cost Basis  Value  Gains  (Losses)  Net 2011:               Maturities greater than ten years:               Auction rate securities $2,600  $2,392  $-  $(208) $(208)Investments without stated maturity dates:                            Auction rate securities  1,000   940   -   (60)  (60)   $3,600  $3,332  $-  $(268) $(268)   Amortized  Fair  Unrealized Holding    Cost Basis  Value  Gains  (Losses)  Net 2010:               Maturities greater than ten years:               Auction rate securities $2,900  $2,668  $-  $(232) $(232)Investments without stated maturity dates:                            Auction rate securities  1,000   940   -   (60)  (60)   $3,900  $3,608  $-  $(292) $(292)We compute the cost of its investments on a specific identification basis. Such cost includes the direct costs to acquire the securities, adjusted for the amortization of any discount or premium.The following table shows the gross unrealized losses and fair value of our marketable securities with unrealized losses that are not deemed to be other-than-temporarily impaired, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, at December 31, 2011 and 2010.2011:   Less than 12 Months  12 Months or Greater  Total Description of Securities Fair Value  UnrealizedLosses  Fair Value  UnrealizedLosses  Fair Value  UnrealizedLosses                     Auction rate securities $-  $-  $3,332  $(268) $3,332  $(268)Total $-  $-  $3,332  $(268) $3,332  $(268)2010:   Less than 12 Months  12 Months or Greater  Total Description of Securities Fair Value  UnrealizedLosses  Fair Value  UnrealizedLosses  Fair Value  UnrealizedLosses                     Auction rate securities $-  $-  $3,608  $(292) $3,608  $(292)Total $-  $-  $3,608  $(292) $3,608  $(292)Other-than-temporary impairment analysis on auction rate securities. The unrealized losses in our auction rate securities investments were the result of an internal analysis of timing of expected future successful auctions, collateralization of underlying assets of the security and credit quality of the security. At December 31, 2011 and 2010, there were two securities with a gross unrealized loss position of $268 and $292 ($3,332 and $3,608 of the total fair value), respectively.The severity of the unrealized losses for auction rate securities at December 31, 2011 and 2010 was ranged from 6 percent and 8 percent below amortized cost, and the weighted average duration of the unrealized losses for these securities was 46 and 34 months, respectively.We have evaluated our individual auction rate securities holdings for other-than-temporary impairment and determined that the unrealized losses as of December 31, 2011 and 2010 are attributable to uncertainty in the liquidity of the auction rate security market. Because we do not intend to sell these securities, and believe it is not more likely than not that we would be required to sell these securities before recovery of principal, we do not consider these securities to be other-than-temporarily impaired at December 31, 2011 and 2010. |

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| - Definition
The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.
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