2.2.0.25falsefalse0211 - Disclosure - Share-Based Compensationtruefalsefalse1falsefalseUSDfalsefalse1/1/2011 - 3/31/2011 USD ($) USD ($) / shares $Jan-01-2011_Mar-31-2011http://www.sec.gov/CIK0000757011duration2011-01-01T00:00:002011-03-31T00:00:00USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDEPSDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0SharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0USDUSD$2true0us-gaap_ShareBasedCompensationAbstractus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNo definition available.falsefalseShare-Based Compensation [Abstract]3false0us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlockus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00  <div style="font-family: 'Times New Roman',Times,serif"> <div align="left" style="font-size: 10pt; margin-top: 12pt"><b>11. Share-Based Compensation</b> </div> <div align="left" style="font-size: 10pt; margin-top: 6pt">During the first quarter of 2011, we granted share-based compensation to eligible participants under our Long-Term Incentive Plan. We recognize expense on all share-based grants over the service period, which is the shorter of the period until the employees’ retirement eligibility dates or the service period of the award for awards expected to vest. Expense is generally reduced for estimated forfeitures. </div> <div align="left" style="font-size: 10pt; margin-top: 12pt">STOCK OPTIONS<br /><br style="font-size: 6pt" /> We granted stock options to purchase 662,032 shares of common stock during the first quarter of 2011 with an exercise price equal to the closing price of our common stock on the date of grant. The stock options generally become exercisable in four equal annual installments beginning one year from the date of grant, although they may become exercisable earlier in the event of death, disability, retirement or a change in control. The stock options generally expire 10 years from the date of grant, or earlier in the event of death, disability or retirement. </div> <div align="left" style="font-size: 10pt; margin-top: 6pt">     We estimated the fair value of each stock option granted to be $10.60 on the date of grant using a Black-Scholes option valuation model that uses the assumptions noted below. We based expected volatility on a 50% weighting of our historical volatilities and 50% weighting of our implied volatilities. The risk-free rate was based on zero coupon U.S. government issues at the time of grant. The expected term was developed using the simplified method, as permitted by the SEC because there is not sufficient historical stock option exercise experience available. </div> <div align="left" style="font-size: 10pt; margin-top: 6pt">     The assumptions used in the valuation were as follows: expected volatility 55.88%, risk-free rate 2.85%, expected term (in years) 6.25 and expected dividends 0. </div> <div align="left" style="font-size: 10pt; margin-top: 12pt">RESTRICTED STOCK UNITS<br /><br style="font-size: 6pt" /> We granted RSUs with respect to 440,401 shares of common stock during the first quarter of 2011 that generally vest in four equal annual installments beginning one year from the date of grant. During the first quarter of 2011, we also granted RSUs with respect to 35,000 shares of common stock that will vest in four equal annual installments beginning one year from the date of grant as a special retention award and with respect to an additional 35,000 shares of common stock that will vest upon the satisfaction of a specified performance goal. Generally, RSUs may vest earlier in the case of death, disability, retirement or a change in control. Each RSU is settled in a share of our common stock after the vesting period. The fair value of each RSU granted is equal to the closing price of our common stock on the date of grant. Virtually all RSUs granted in the first quarter of 2011 had a fair value of $18.99. </div> <div align="left" style="font-size: 10pt; margin-top: 12pt">PERFORMANCE SHARES<br /><br style="font-size: 6pt" /> We granted 227,539 performance shares during the first quarter of 2011. The performance shares generally vest after a three-year period based on our total stockholder return relative to the performance of the Dow Jones U.S. Construction and Materials Index, with adjustments to that index in certain circumstances, for the three-year period. The number of performance shares earned will vary from 0 to 200% of the number of performance shares awarded depending on that relative performance. Vesting will be pro-rated based on the number of full months employed during the performance period in the case of death, disability, retirement or a change-in-control, and pro-rated awards earned will be paid at the end of the three-year period. Each performance share earned will be settled in a share of our common stock. </div> <div align="left" style="font-size: 10pt; margin-top: 6pt">     We estimated the fair value of each performance share granted to be $28.40 on the date of grant using a Monte Carlo simulation that uses the assumptions noted below. Expected volatility is based on implied volatility of our traded options and the daily historical volatilities of our peer group. The risk-free rate was based on zero coupon U.S. government issues at the time of grant. The expected term represents the period from the valuation date to the end of the performance period. </div> <div align="left" style="font-size: 10pt; margin-top: 6pt">     The assumptions used in the valuation were as follows: expected volatility 77.84%, risk-free rate 1.20%, expected term (in years) 2.89 and expected dividends 0. </div> </div>  <!-- Begin Block Tagged NotefalsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringDisclosure of compensation-related costs for share-based compensation which may include disclosure of policies, compensation plan details, allocation of stock compensation, incentive distributions, share-based arrangements to obtain goods and services, deferred compensation arrangements, employee stock ownership plan details and employee stock purchase plan details.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 123R -Paragraph 64, 65, A240 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Statement of Position (SOP) -Number 93-6 -Paragraph 53 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 14 falsefalseShare-Based Compensation12Share-Based CompensationUnKnownUnKnownUnKnownUnKnownfalsetrue