2.2.0.25falsefalse10600 - Disclosure - Stock-Based Compensationtruefalsefalse1falsefalseUSDfalsefalse1/1/2011 - 3/31/2011 USD ($) USD ($) / shares $FROM_Jan01_2011_TO_Mar31_2011http://www.sec.gov/CIK0000073020duration2011-01-01T00:00:002011-03-31T00:00:00USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170SharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0USDpershareDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0USDUSD$2true0nwn_DisclosureStockBasedCompensationnwnfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNo definition available.falsefalseDisclosure - Stock Based Compensation3false0us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlockus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse006.       Stock-Based Compensation We have several stock-based compensation plans, including a Long-Term Incentive Plan (LTIP), a Restated Stock Option Plan (Restated SOP) and an Employee Stock Purchase Plan.  These plans are designed to promote stock ownership in NW Natural by employees and officers.  For additional information on our stock-based compensation plans, see Part II, Item 8., Note 6, in the 2010 Form 10-K and current updates provided below. Long-Term Incentive Plan.  On February 23, 2011, 37,950 performance-based shares were granted under the LTIP, which include a market condition, based on target-level awards and a weighted-average grant date fair value of $25.25 per share.  Fair value was estimated as of the date of grant using a Monte-Carlo option pricing model based on the following assumptions:<div><table style="border-collapse:collapse;margin-top:20px;"><tr style="height: 20px"><td style="width: 625px; border-top-style:solid;border-top-width:1px;text-align:left;border-color:#000000;min-width:625px;">Stock price on valuation date</td><td style="width: 15px; border-top-style:solid;border-top-width:1px;text-align:right;border-color:#000000;min-width:15px;">$</td><td style="width: 60px; border-top-style:solid;border-top-width:1px;text-align:right;border-color:#000000;min-width:60px;">45.74</td><td style="width: 20px; border-top-style:solid;border-top-width:1px;text-align:right;border-color:#000000;min-width:20px;"> </td></tr><tr style="height: 20px"><td style="width: 625px; text-align:left;border-color:#000000;min-width:625px;">Performance term (in years)</td><td style="width: 15px; text-align:right;border-color:#000000;min-width:15px;"> </td><td style="width: 60px; text-align:right;border-color:#000000;min-width:60px;">3.0</td><td style="width: 20px; text-align:right;border-color:#000000;min-width:20px;"> </td></tr><tr style="height: 20px"><td style="width: 625px; text-align:left;border-color:#000000;min-width:625px;">Quarterly dividends paid per share</td><td style="width: 15px; text-align:right;border-color:#000000;min-width:15px;">$</td><td style="width: 60px; text-align:right;border-color:#000000;min-width:60px;">0.435</td><td style="width: 20px; text-align:right;border-color:#000000;min-width:20px;"> </td></tr><tr style="height: 20px"><td style="width: 625px; text-align:left;border-color:#000000;min-width:625px;">Expected dividend yield</td><td style="width: 15px; text-align:right;border-color:#000000;min-width:15px;"> </td><td style="width: 60px; text-align:right;border-color:#000000;min-width:60px;">3.7</td><td style="width: 20px; text-align:left;border-color:#000000;min-width:20px;">%</td></tr><tr style="height: 20px"><td style="width: 625px; border-bottom-style:solid;border-bottom-width:1px;text-align:left;border-color:#000000;min-width:625px;">Dividend discount factor</td><td style="width: 15px; border-bottom-style:solid;border-bottom-width:1px;text-align:right;border-color:#000000;min-width:15px;"> </td><td style="width: 60px; border-bottom-style:solid;border-bottom-width:1px;text-align:right;border-color:#000000;min-width:60px;"> 0.8930</td><td style="width: 20px; border-bottom-style:solid;border-bottom-width:1px;text-align:right;border-color:#000000;min-width:20px;"> </td></tr></table></div>In February 2011, the Board approved a payout of performance-based stock awards under the LTIP for the 2008-10 award period.  Shares of common stock were purchased on the open market to satisfy these awards. Restated Stock Option Plan.  On February 23, 2011, options to purchase 122,700 shares were granted under the Restated SOP, with an exercise price equal to the closing market price of $45.74 per share on the date of grant, vesting over a four-year period following the date of grant and with a term of 10 years and 7 days. The weighted-average grant date fair value was $6.73 per share.  Fair value was estimated as of the date of grant using the Black-Scholes option pricing model based on the following assumptions: <div><table style="border-collapse:collapse;margin-top:20px;"><tr style="height: 20px"><td style="width: 600px; border-top-style:solid;border-top-width:1px;text-align:left;border-color:#000000;min-width:600px;">Risk-free interest rate</td><td style="width: 100px; border-top-style:solid;border-top-width:1px;text-align:right;border-color:#000000;min-width:100px;">2.0</td><td style="width: 20px; border-top-style:solid;border-top-width:1px;text-align:left;border-color:#000000;min-width:20px;">%</td></tr><tr style="height: 20px"><td style="width: 600px; text-align:left;border-color:#000000;min-width:600px;">Expected life (in years)</td><td style="width: 100px; text-align:right;border-color:#000000;min-width:100px;">4.5</td><td style="width: 20px; text-align:left;border-color:#000000;min-width:20px;"> </td></tr><tr style="height: 20px"><td style="width: 600px; text-align:left;border-color:#000000;min-width:600px;">Expected market price volatility factor</td><td style="width: 100px; text-align:right;border-color:#000000;min-width:100px;">24.5</td><td style="width: 20px; text-align:left;border-color:#000000;min-width:20px;">%</td></tr><tr style="height: 20px"><td style="width: 600px; text-align:left;border-color:#000000;min-width:600px;">Expected dividend yield</td><td style="width: 100px; text-align:right;border-color:#000000;min-width:100px;">3.8</td><td style="width: 20px; text-align:left;border-color:#000000;min-width:20px;">%</td></tr><tr style="height: 20px"><td style="width: 600px; border-bottom-style:solid;border-bottom-width:1px;text-align:left;border-color:#000000;min-width:600px;">Forfeiture rate</td><td style="width: 100px; border-bottom-style:solid;border-bottom-width:1px;text-align:right;border-color:#000000;min-width:100px;">3.1</td><td style="width: 20px; border-bottom-style:solid;border-bottom-width:1px;text-align:left;border-color:#000000;min-width:20px;">%</td></tr></table></div>As of March 31, 2011, there was $1.3 million of unrecognized compensation cost related to the unvested portion of outstanding Restated SOP awards expected to be recognized over a period extending through 2014.   6.       Stock-Based Compensation We have several stock-based compensation plans, including a Long-Term Incentive PlanfalsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringDisclosure of components of a stock option or other award plan under which share-based compensation is awarded to employees, typically comprised of the amount of unearned compensation (deferred compensation cost), compensation expense, and changes in the quantity and fair value of the shares granted, exercised, forfeited, and issued and outstanding pertaining to that plan. Disclosure may also include nature and general terms of such arrangements that existed during the period and potential effects of those arrangements on shareholders, effect of compensation cost arising from share-based payment arrangements on the income statement, method of estimating the fair value of the goods or services received, or the fair value of the equity instruments granted, during the period, cash flow effects resulting from share-based payment arrangements and, for registrants that accelerate vesting of out of the money share options, reasons for the decision to accelerate.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 123R -Paragraph 64, 65, A240 falsefalseStock Based Compensation Text Block12Stock-Based CompensationUnKnownUnKnownUnKnownUnKnownfalsetrue