| **Financial Instruments and Fair Value Measurements** | 9 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 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| **Fair Value Disclosures [Abstract]**                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      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| Financial Instruments and Fair Value Measurements     | Financial Instruments and Fair Value MeasurementsFair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or a liability. A three-tier fair value hierarchy is established as a basis for considering such assumptions and for inputs used in the valuation methodologies in measuring fair value:Level 1. Quoted prices in active markets for identical assets or liabilities;Level 2. Inputs, other than the quoted prices in active markets, that are observable either directly or indirectly; andLevel 3. Unobservable inputs in which there is little or no market data, such as internally-developed valuation models which require the reporting entity to develop its own assumptions.The financial instruments measured at fair value on a recurring basis at September 30, 2013 were as follows: Level 1 Level 2 Level 3 Total Fair ValueMoney market funds$2,444 $— $— $2,444Debt securities:       U.S. treasury securities124,973 — — 124,973Corporate debt securities— 21,078 — 21,078 $127,417 $21,078 $— $148,495Money market funds and U.S. Treasury securities are measured based on quoted market prices in an active market and categorized within Level 1 of the fair value hierarchy.Corporate debt securities are measured primarily using pricing data from external pricing services that use prices observed for recently executed market transactions. Corporate debt securities are categorized as level 2 financial instruments since their fair values were determined from quoted prices in an inactive market or for similar instruments in an active market. The Company did not have any financial instruments measured at fair value on a recurring basis at December 31, 2012.Fair Value of Financial InstrumentsThe Company uses the following methods and assumptions in estimating fair value for financial instruments:•The fair values of cash and cash equivalents, accounts payable and accrued liabilities, approximate their carrying values at September 30, 2013 and December 31, 2012, due to the short-term nature of these assets and liabilities. These financial instruments would be categorized as level 1. The Company’s notes receivable and debt is at rates that approximate current market rates for these instruments. These financial instruments would be categorized as level 2.•The fair value of the Company’s pledged treasury securities are based on quoted market rates.•The fair value of the Company’s retained interest investment is the present value of the expected future cash flows at the effective yield.The carrying amount and fair value of the Company’s financial instruments were as follows (the table below excludes financial instruments with carrying values that approximate their fair values): September 30, 2013 December 31, 2012 Carrying value Fair value Level Carrying value Fair value LevelAssets           Pledged treasury securities$26,404 $28,965 1 $26,818 $30,432 1Retained interest investment$9,567 $12,711 3 $9,481 $12,392 3Pledged Treasury SecuritiesIn connection with a sale of the Company's office portfolio in 2007, the Company completed an in-substance defeasance of approximately $29.3 million of mortgage debt that was collateralized by one of the commercial buildings. The Company assigned the mortgage debt and deposited sufficient funds with a trustee solely to satisfy the principal and remaining interest obligations on the mortgage debt when due. The interest yield on the pledged securities and the interest expense on the debt are closely related. The transaction did not qualify as an extinguishment of debt, since the Company is responsible if there would be a shortfall in the funds deposited into the trust, which are invested in government backed securities. The trust is not in the Company’s control and the trustee cannot sell the securities prior to maturity.As such, the government backed securities and the related debt (see Note 8, Debt) remain on the Company’s Condensed Consolidated Balance Sheets at September 30, 2013 and December 31, 2012. The government backed securities are recorded as Pledged treasury securities on the Company’s Condensed Consolidated Balance Sheets and are classified as held-to-maturity because the Company has both the intent and the ability since it is a contractual obligation of the assuming entity to hold the securities to maturity. Accordingly, the Company has recorded the pledged treasury securities at cost, adjusted for the amortization of the discount.Retained Interest InvestmentsDuring 2008 and 2007, the Company sold 132,055 acres of timberland in exchange for fifteen year installment notes receivable in the aggregate amount of $183.3 million. The installment notes are fully backed by irrevocable letters of credit. The Company contributed the installment notes to bankruptcy remote qualified special purpose entities (the “Entities”).During 2008 and 2007, the Entities monetized $183.3 million of installment notes by issuing debt securities to third party investors equal to approximately 90% of the value of the installment notes. The Company received approximately $163.0 million in net proceeds during 2008 and 2007. The debt securities are payable solely out of the assets of the Entities and proceeds from the letters of credit. The investors in the Entities have no recourse against the Company for payment of the debt securities or related interest expense. The Entities’ financial position and results of operations are not consolidated in the Company’s financial statements, since the Company is not the primary decision maker with respect to activities that could significantly impact the economic performance of the Entities, nor does the Company perform any service activity related to the Entities.At the time of monetization the initial retained interest recorded was an estimate based on the present value of future excess cash flows expected to be received over the life of the retained interest, using management’s best estimate of underlying assumptions, including credit risk and discount rates. The Company’s continuing involvement with the Entities is the receipt of the net interest payments and the remaining principal at the end of the installment notes' fifteen year maturity period, in 2022 through 2024.As of September 30, 2013 and December 31, 2012, the Company had a retained interest investment balance of $9.6 million and $9.5 million, respectively, recorded in Other assets on the Company’s Condensed Consolidated Balance Sheets. The Company has classified its retained interest investment as held-to-maturity because the Company has both the intent and the ability to hold its interest in the Entities to maturity. Accordingly, the Company has recorded the retained interest investment at cost, adjusted for the accretion of investment income over the life of the retained interest using the effective yield method with rates ranging from 3.7% - 12.4%. The Company continues to update the expectation of cash flows to be collected over the term of the retained interest. Changes to the previously projected cash flows are accounted for prospectively, unless based on management’s assessment of current information and events, it is determined that there is an other-than-temporary impairment. The Company has not recorded an other-than-temporary impairment related to its retained interest investments during the three and nine months ended September 30, 2013 and 2012.In the event of a failure and liquidation of the counterparties involved in the installment sales, the Company could be required to write-off the remaining retained interest recorded on its condensed consolidated balance sheets in connection with the installment sale monetization transactions. |

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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.
+ References
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