1.0.0.3 true CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY AND COMPREHENSIVE INCOME (USD $) In Thousands false 1 $ true false false false Common Stock us-gaap_StatementEquityComponentsAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_CommonStockMember us-gaap_StatementEquityComponentsAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 false 2 $ true false false false Capital in Excess of Par Value us-gaap_StatementEquityComponentsAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_AdditionalPaidInCapitalMember us-gaap_StatementEquityComponentsAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 false 3 $ true false false false Retained Earnings (Deficit) us-gaap_StatementEquityComponentsAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_RetainedEarningsMember us-gaap_StatementEquityComponentsAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 false 4 $ true false false false Treasury Stock us-gaap_StatementEquityComponentsAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_TreasuryStockMember us-gaap_StatementEquityComponentsAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 false 5 $ true false false false Accumulated Other Comprehensive Income (Loss) us-gaap_StatementEquityComponentsAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_AccumulatedOtherComprehensiveIncomeMember us-gaap_StatementEquityComponentsAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 false 6 $ false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 USDPerShare Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 6 Balance, previously reported at Dec. 31, 2006 4 wlt_BalanceAsPreviouslyReported wlt false credit instant monetary No definition available. false false false true false false true false false 1 true true 728000 728 true false 2 true true 757699000 757699 true false 3 true true -398564000 -398564 true false 4 true true -259317000 -259317 true false 5 true true -98638000 -98638 true false 6 true true 1908000 1908 false false No definition available. No authoritative reference available. false 8 Balance at Dec. 31, 2006 4 us-gaap_StockholdersEquity us-gaap true credit instant monetary No definition available. false false false true false false true false false 1 false true 728000 728 true false 2 false true 757699000 757699 true false 3 false true -402985000 -402985 true false 4 false true -259317000 -259317 true false 5 false true -98638000 -98638 true false 6 false true -2513000 -2513 false false No definition available. No authoritative reference available. false 5 Increase (Decrease) in Stockholders' Equity 3 us-gaap_IncreaseDecreaseInStockholdersEquityRollForward us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false false 0 0 false false No definition available. false 7 Adjustment to initially apply FIN 48 4 us-gaap_CumulativeEffectOfInitialAdoptionOfFIN48 us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false true -4421000 -4421 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false true -4421000 -4421 false false No definition available. No authoritative reference available. false 9 Comprehensive income: 4 us-gaap_ComprehensiveIncomeNetOfTaxAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false false 0 0 false false No definition available. false 10 Net income 5 us-gaap_NetIncomeLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false true 111999000 111999 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false true 111999000 111999 false false No definition available. No authoritative reference available. false 11 Other comprehensive income, net of tax: 5 us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false false 0 0 false false No definition available. false 12 Change in pension and postretirement benefit plans, net of tax benefit of $44.2 million for 2009, tax benefit of $32.3 million for 2008 and tax provision of $9.7 million for 2007 6 us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false false 0 0 true false 5 false true 15231000 15231 true false 6 false true 15231000 15231 false false No definition available. No authoritative reference available. false 13 Change in unrealized gain (loss) on hedges, net of $0.4 million tax for 2009, $4.5 million tax provision for 2008 and $4.3 million tax benefit for 2007 6 us-gaap_OtherComprehensiveIncomeDerivativesQualifyingAsHedgesNetOfTaxPortionAttributableToParent us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false false 0 0 true false 5 false true -8446000 -8446 true false 6 false true -8446000 -8446 false false No definition available. No authoritative reference available. false 14 Comprehensive income 5 us-gaap_ComprehensiveIncomeNetOfTax us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false true 118784000 118784 false false No definition available. No authoritative reference available. true 15 Effects of changing the pension plan measurement date pursuant to FASB Statement No. 158: 4 us-gaap_ChangeInMeasurementDateSFAS158Abstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false false 0 0 false false No definition available. false 18 Retirement of treasury stock 4 us-gaap_TreasuryStockValueAcquiredCostMethod us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true -207000 -207 true false 2 false true -259902000 -259902 true false 3 false false 0 0 true false 4 false true 260109000 260109 true false 5 false false 0 0 true false 6 false false 0 0 false false No definition available. No authoritative reference available. false 20 Purchases of stock under stock repurchase program 4 us-gaap_StockRepurchasedAndRetiredDuringPeriodValue us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true -1000 -1 true false 2 false true -5626000 -5626 true false 3 false false 0 0 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false true -5627000 -5627 false false No definition available. No authoritative reference available. false 21 Stock issued upon the exercise of stock options 4 us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false true 1447000 1447 true false 3 false false 0 0 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false true 1447000 1447 false false No definition available. No authoritative reference available. false 23 Tax benefit on the exercise of stock options 4 us-gaap_TaxBenefitFromStockOptionsExercised us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false true 2015000 2015 true false 3 false false 0 0 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false true 2015000 2015 false false No definition available. No authoritative reference available. false 25 Dividends paid $0.40 per share for year 2009, $ 0.30 per share for year 2008 and $0.20 per share for year 2007 4 us-gaap_DividendsCommonStockCash us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false true -10411000 -10411 true false 3 false false 0 0 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false true -10411000 -10411 false false No definition available. No authoritative reference available. false 26 Stock based compensation 4 us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false true 11810000 11810 true false 3 false false 0 0 true false 4 false false 0 0 true false 5 false false 0 0 true false 6 false true 11810000 11810 false false No definition available. No authoritative reference available. false 27 Other 4 us-gaap_StockholdersEquityOther us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false true -792000 -792 true false 5 false false 0 0 true false 6 false true -792000 -792 false false No definition available. No authoritative reference available. false 29 Balance at Dec. 31, 2007 4 us-gaap_StockholdersEquity us-gaap true credit instant monetary No definition available. false false false true false false false true false 1 false true 520000 520 true false 2 false true 497032000 497032 true false 3 false true -290986000 -290986 true false 4 false false 0 0 true false 5 false true -91853000 -91853 true false 6 false true 114713000 114713 false false No definition available. No authoritative reference available. false 9 Comprehensive income: 4 us-gaap_ComprehensiveIncomeNetOfTaxAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false false 0 0 false false 5 false false 0 0 true false 6 false false 0 0 false false No definition available. false 10 Net income 5 us-gaap_NetIncomeLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false true 346580000 346580 true false 4 false false 0 0 false false 5 false false 0 0 true false 6 false true 346580000 346580 false false No definition available. No authoritative reference available. false 11 Other comprehensive income, net of tax: 5 us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false false 0 0 false false 5 false false 0 0 true false 6 false false 0 0 false false No definition available. false 12 Change in pension and postretirement benefit plans, net of tax benefit of $44.2 million for 2009, tax benefit of $32.3 million for 2008 and tax provision of $9.7 million for 2007 6 us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false false 0 0 false false 5 false true -50961000 -50961 true false 6 false true -50961000 -50961 false false No definition available. No authoritative reference available. false 13 Change in unrealized gain (loss) on hedges, net of $0.4 million tax for 2009, $4.5 million tax provision for 2008 and $4.3 million tax benefit for 2007 6 us-gaap_OtherComprehensiveIncomeDerivativesQualifyingAsHedgesNetOfTaxPortionAttributableToParent us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false false 0 0 false false 5 false true 6710000 6710 true false 6 false true 6710000 6710 false false No definition available. No authoritative reference available. false 14 Comprehensive income 5 us-gaap_ComprehensiveIncomeNetOfTax us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false false 0 0 false false 5 false false 0 0 true false 6 false true 302329000 302329 false false No definition available. No authoritative reference available. true 15 Effects of changing the pension plan measurement date pursuant to FASB Statement No. 158: 4 us-gaap_ChangeInMeasurementDateSFAS158Abstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false false 0 0 false false 5 false false 0 0 true false 6 false false 0 0 false false No definition available. false 16 Service cost, interest cost, and expected return on plan assets for October 1-December 31, 2007, net of $3.0 million tax benefit 5 us-gaap_EffectOnRetainedEarningsAccumulatedDeficitDueToChangeInMeasurementDateNetOfTax us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false true -4604000 -4604 true false 4 false false 0 0 false false 5 false false 0 0 true false 6 false true -4604000 -4604 false false No definition available. No authoritative reference available. false 17 Amortization of prior service cost and actuarial gain/loss for October 1-December 31, 2007, net of $0.5 million tax provision 5 us-gaap_EffectOnOtherComprehensiveIncomeLossDueToChangeInMeasurementDateNetOfTax us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false false 0 0 false false 5 false true 668000 668 true false 6 false true 668000 668 false false No definition available. No authoritative reference available. false 19 Proceeds from public stock offering 4 us-gaap_ProceedsFromIssuanceInitialPublicOffering us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 32000 32 true false 2 false true 280432000 280432 true false 3 false false 0 0 true false 4 false false 0 0 false false 5 false false 0 0 true false 6 false true 280464000 280464 false false No definition available. No authoritative reference available. false 20 Purchases of stock under stock repurchase program 4 us-gaap_StockRepurchasedAndRetiredDuringPeriodValue us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true -16000 -16 true false 2 false true -64628000 -64628 true false 3 false false 0 0 true false 4 false false 0 0 false false 5 false false 0 0 true false 6 false true -64644000 -64644 false false No definition available. No authoritative reference available. false 21 Stock issued upon the exercise of stock options 4 us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 4000 4 true false 2 false true 7989000 7989 true false 3 false false 0 0 true false 4 false false 0 0 false false 5 false false 0 0 true false 6 false true 7993000 7993 false false No definition available. No authoritative reference available. false 22 Stock issued upon conversion of convertible notes 4 us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 1000 1 true false 2 false true 784000 784 true false 3 false false 0 0 true false 4 false false 0 0 false false 5 false false 0 0 true false 6 false true 785000 785 false false No definition available. No authoritative reference available. false 25 Dividends paid $0.40 per share for year 2009, $ 0.30 per share for year 2008 and $0.20 per share for year 2007 4 us-gaap_DividendsCommonStockCash us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false true -16233000 -16233 true false 3 false false 0 0 true false 4 false false 0 0 false false 5 false false 0 0 true false 6 false true -16233000 -16233 false false No definition available. No authoritative reference available. false 26 Stock based compensation 4 us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false true 10439000 10439 true false 3 false false 0 0 true false 4 false false 0 0 false false 5 false false 0 0 true false 6 false true 10439000 10439 false false No definition available. No authoritative reference available. false 27 Other 4 us-gaap_StockholdersEquityOther us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false true -1641000 -1641 true false 3 false false 0 0 true false 4 false false 0 0 false false 5 false false 0 0 true false 6 false true -1641000 -1641 false false No definition available. No authoritative reference available. false 29 Balance at Dec. 31, 2008 4 us-gaap_StockholdersEquity us-gaap true credit instant monetary No definition available. false false false true false false false true false 1 false true 541000 541 true false 2 false true 714174000 714174 true false 3 false true 50990000 50990 true false 4 false false 0 0 false false 5 false true -135436000 -135436 true false 6 false true 630269000 630269 false false No definition available. No authoritative reference available. false 9 Comprehensive income: 4 us-gaap_ComprehensiveIncomeNetOfTaxAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false false 0 0 false false 5 false false 0 0 true false 6 false false 0 0 false false No definition available. false 10 Net income 5 us-gaap_NetIncomeLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false true 137158000 137158 true false 4 false false 0 0 false false 5 false false 0 0 true false 6 false true 137158000 137158 false false No definition available. No authoritative reference available. false 11 Other comprehensive income, net of tax: 5 us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false false 0 0 false false 5 false false 0 0 true false 6 false false 0 0 false false No definition available. false 12 Change in pension and postretirement benefit plans, net of tax benefit of $44.2 million for 2009, tax benefit of $32.3 million for 2008 and tax provision of $9.7 million for 2007 6 us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false false 0 0 false false 5 false true -28513000 -28513 true false 6 false true -28513000 -28513 false false No definition available. No authoritative reference available. false 13 Change in unrealized gain (loss) on hedges, net of $0.4 million tax for 2009, $4.5 million tax provision for 2008 and $4.3 million tax benefit for 2007 6 us-gaap_OtherComprehensiveIncomeDerivativesQualifyingAsHedgesNetOfTaxPortionAttributableToParent us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false false 0 0 false false 5 false true -877000 -877 true false 6 false true -877000 -877 false false No definition available. No authoritative reference available. false 14 Comprehensive income 5 us-gaap_ComprehensiveIncomeNetOfTax us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false false 0 0 false false 5 false false 0 0 true false 6 false true 107768000 107768 false false No definition available. No authoritative reference available. true 15 Effects of changing the pension plan measurement date pursuant to FASB Statement No. 158: 4 us-gaap_ChangeInMeasurementDateSFAS158Abstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false false 0 0 true false 4 false false 0 0 false false 5 false false 0 0 true false 6 false false 0 0 false false No definition available. false 20 Purchases of stock under stock repurchase program 4 us-gaap_StockRepurchasedAndRetiredDuringPeriodValue us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true -14000 -14 true false 2 false true -34240000 -34240 true false 3 false false 0 0 true false 4 false false 0 0 false false 5 false false 0 0 true false 6 false true -34254000 -34254 false false No definition available. No authoritative reference available. false 21 Stock issued upon the exercise of stock options 4 us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 6000 6 true false 2 false true 9882000 9882 true false 3 false false 0 0 true false 4 false false 0 0 false false 5 false false 0 0 true false 6 false true 9888000 9888 false false No definition available. No authoritative reference available. false 24 Stock dividend for spin-off of Financing 4 us-gaap_StockIssuedDuringPeriodValueStockDividend us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false true -321301000 -321301 true false 3 false true -116106000 -116106 true false 4 false false 0 0 false false 5 false true -1686000 -1686 true false 6 false true -439093000 -439093 false false No definition available. No authoritative reference available. false 25 Dividends paid $0.40 per share for year 2009, $ 0.30 per share for year 2008 and $0.20 per share for year 2007 4 us-gaap_DividendsCommonStockCash us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false false 0 0 true false 3 false true -21190000 -21190 true false 4 false false 0 0 false false 5 false false 0 0 true false 6 false true -21190000 -21190 false false No definition available. No authoritative reference available. false 26 Stock based compensation 4 us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false true 6703000 6703 true false 3 false false 0 0 true false 4 false false 0 0 false false 5 false false 0 0 true false 6 false true 6703000 6703 false false No definition available. No authoritative reference available. false 27 Other 4 us-gaap_StockholdersEquityOther us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 true false 2 false true -696000 -696 true false 3 false false 0 0 true false 4 false false 0 0 false false 5 false false 0 0 true false 6 false true -696000 -696 false false No definition available. No authoritative reference available. false 29 Balance at Dec. 31, 2009 4 us-gaap_StockholdersEquity us-gaap true credit instant monetary No definition available. false false false true false false false true false 1 true true 533000 533 true false 2 true true 374522000 374522 true false 3 true true 50852000 50852 true false 4 false false 0 0 false false 5 true true -166512000 -166512 true false 6 true true 259395000 259395 false false No definition available. No authoritative reference available. false false 6 50 false Thousands UnKnown UnKnown false true