1.0.0.3 false CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands false 1 $ 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 false 2 $ 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 false 3 $ 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 false 4 $ 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 3 OPERATING ACTIVITIES 1 us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false 4 false false 0 0 false false No definition available. false 4 Net income 2 us-gaap_NetIncomeLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 true true 23808000 23808 false false 2 true true 55000000 55000 false false 3 true true 107982000 107982 false false 4 true true 106275000 106275 false false No definition available. No authoritative reference available. false 5 Loss from discontinued operations 2 us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 560000 560 false false 2 false true 16290000 16290 false false 3 false true 572000 572 false false 4 false true 27926000 27926 false false No definition available. No authoritative reference available. false 6 Income from continuing operations 2 us-gaap_IncomeLossFromContinuingOperations us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 24368000 24368 false false 2 false true 71290000 71290 false false 3 false true 108554000 108554 false false 4 false true 134201000 134201 false false No definition available. No authoritative reference available. true 7 Adjustments to reconcile income from continuing operations to net cash provided by operating activities: 2 us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false 4 false false 0 0 false false No definition available. false 8 Depreciation 3 us-gaap_Depreciation us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 18214000 18214 false false 2 false true 13525000 13525 false false 3 false true 54216000 54216 false false 4 false true 37833000 37833 false false No definition available. No authoritative reference available. false 9 Other 3 us-gaap_AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesOther us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true 21077000 21077 false false 4 false true 6188000 6188 false false No definition available. No authoritative reference available. false 10 Decrease (increase) in current assets: 2 us-gaap_IncreaseDecreaseInOperatingAssetsAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false 4 false false 0 0 false false No definition available. false 11 Receivables 3 us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true 18126000 18126 false false 4 false true -71658000 -71658 false false No definition available. No authoritative reference available. false 12 Inventories 3 us-gaap_IncreaseDecreaseInInventories us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true -30213000 -30213 false false 4 false true -23645000 -23645 false false No definition available. No authoritative reference available. false 13 Other current assets 3 us-gaap_IncreaseDecreaseInOtherOperatingAssets us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true 11267000 11267 false false 4 false true 7049000 7049 false false No definition available. No authoritative reference available. false 14 Increase (decrease) in current liabilities: 2 us-gaap_IncreaseDecreaseInOperatingLiabilitiesAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false 4 false false 0 0 false false No definition available. false 15 Accounts payable 3 us-gaap_IncreaseDecreaseInAccountsPayable us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true -12126000 -12126 false false 4 false true 11780000 11780 false false No definition available. No authoritative reference available. false 16 Accrued expenses and other current liabilities 3 us-gaap_IncreaseDecreaseInAccruedLiabilities us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true -6131000 -6131 false false 4 false true 35168000 35168 false false No definition available. No authoritative reference available. false 17 Cash flows provided by (used in) operating activities 2 us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations us-gaap true na duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true 164770000 164770 false false 4 false true 136916000 136916 false false No definition available. No authoritative reference available. true 18 INVESTING ACTIVITIES 1 us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false 4 false false 0 0 false false No definition available. false 19 Additions to property, plant and equipment 2 us-gaap_PaymentsToAcquirePropertyPlantAndEquipment us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true -67312000 -67312 false false 4 false true -83768000 -83768 false false No definition available. No authoritative reference available. false 20 Acquisition of Taft Coal Sales & Associates, Inc. 2 us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false 4 false true -17871000 -17871 false false No definition available. No authoritative reference available. false 21 Other 2 us-gaap_PaymentsForProceedsFromOtherInvestingActivities us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true 3667000 3667 false false 4 false true -364000 -364 false false No definition available. No authoritative reference available. false 22 Cash flows provided by (used in) investing activities 2 us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true -63645000 -63645 false false 4 false true -102003000 -102003 false false No definition available. No authoritative reference available. true 23 FINANCING ACTIVITIES 1 us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false 4 false false 0 0 false false No definition available. false 24 Proceeds from issuance of debt 2 us-gaap_ProceedsFromIssuanceOfLongTermDebt us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false 4 false true 330000000 330000 false false No definition available. No authoritative reference available. false 25 Retirements of debt 2 us-gaap_ProceedsFromRepaymentsOfDebt us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true -55260000 -55260 false false 4 false true -376351000 -376351 false false No definition available. No authoritative reference available. false 26 Proceeds from stock offering 2 us-gaap_ProceedsFromIssuanceOfCommonStock us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false 4 false true 280432000 280432 false false No definition available. No authoritative reference available. false 27 Dividends paid 2 us-gaap_PaymentsOfDividends us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true -15887000 -15887 false false 4 false true -10799000 -10799 false false No definition available. No authoritative reference available. false 28 Cash spun off to Financing 2 wlt_CashRelatedToSpinOffOfASubsidiary wlt false credit duration monetary Cash distributed with ownership spin-off. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true -33821000 -33821 false false 4 false false 0 0 false false Cash distributed with ownership spin-off. No authoritative reference available. false 29 Purchases of stock under stock repurchase program 2 us-gaap_PaymentsForRepurchaseOfCommonStock us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true -27963000 -27963 false false 4 false true -14461000 -14461 false false No definition available. No authoritative reference available. false 30 Other 2 us-gaap_ProceedsFromPaymentsForOtherFinancingActivities us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true -5262000 -5262 false false 4 false true 12096000 12096 false false No definition available. No authoritative reference available. false 31 Cash flows provided by (used in) financing activities 2 us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true -138193000 -138193 false false 4 false true 220917000 220917 false false No definition available. No authoritative reference available. true 32 Cash flows provided by (used in) continuing operations 1 wlt_NetCashProvidedByUsedInContinuingOperations wlt false debit duration monetary The net cash from (used in) the entity's operating activities,excluding those of discontinued operations, of the reporting... false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true -37068000 -37068 false false 4 false true 255830000 255830 false false The net cash from (used in) the entity's operating activities,excluding those of discontinued operations, of the reporting entity. Operating activities generally involve producing and delivering goods and providing services. Operating activity cash flows include transactions, adjustments, and changes in value that are not defined as investing or financing activities. No authoritative reference available. true 33 CASH FLOWS FROM DISCONTINUED OPERATIONS 1 us-gaap_NetCashProvidedByUsedInDiscontinuedOperationsAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false 4 false false 0 0 false false No definition available. false 34 Cash flows provided by (used in) operating activities 2 us-gaap_CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true 24133000 24133 false false 4 false true 22190000 22190 false false No definition available. No authoritative reference available. false 35 Cash flows provided by (used in) investing activities 2 us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true 25732000 25732 false false 4 false true 29116000 29116 false false No definition available. No authoritative reference available. false 36 Cash flows provided by (used in) financing activities 2 us-gaap_CashProvidedByUsedInFinancingActivitiesDiscontinuedOperations us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true -41385000 -41385 false false 4 false true -306559000 -306559 false false No definition available. No authoritative reference available. false 37 Cash flows provided by (used in) discontinued operations 2 us-gaap_NetCashProvidedByUsedInDiscontinuedOperations us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true 8480000 8480 false false 4 false true -255253000 -255253 false false No definition available. No authoritative reference available. true 38 Net increase (decrease) in cash and cash equivalents 1 us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease us-gaap true na duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true -28588000 -28588 false false 4 false true 577000 577 false false No definition available. No authoritative reference available. true 39 Cash and cash equivalents at beginning of period 1 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant monetary No definition available. false false false false false false true false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true 116074000 116074 false false 4 false true 27459000 27459 false false No definition available. No authoritative reference available. false 40 Add: Cash and cash equivalents of discontinued operations at beginning of period 1 us-gaap_DisposalGroupIncludingDiscontinuedOperationCashAndCashEquivalents us-gaap true debit instant monetary No definition available. false false false false false false true false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true 1598000 1598 false false 4 false true 3155000 3155 false false No definition available. No authoritative reference available. false 41 Net increase (decrease) in cash and cash equivalents 1 us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease us-gaap true na duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true -28588000 -28588 false false 4 false true 577000 577 false false No definition available. No authoritative reference available. false 42 Less: Cash and cash equivalents of discontinued operations at end of period 1 us-gaap_DisposalGroupIncludingDiscontinuedOperationCashAndCashEquivalents us-gaap true debit instant monetary No definition available. false false false false false false false true false 1 false true 1269000 1269 false false 2 false true 1644000 1644 false false 3 false true 1269000 1269 false false 4 false true 1644000 1644 false false No definition available. No authoritative reference available. false 43 Cash and cash equivalents at end of period 1 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant monetary No definition available. false false false false false false false true false 1 false true 87815000 87815 false false 2 false true 29547000 29547 false false 3 false true 87815000 87815 false false 4 false true 29547000 29547 false false No definition available. No authoritative reference available. false 45 Non-cash transactions: 2 us-gaap_OtherNoncashInvestingAndFinancingItemsAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false 4 false false 0 0 false false No definition available. false 46 Financing of one-year property insurance policy 3 wlt_PropertyInsurancePolicyFinancingAgreement wlt false debit duration monetary The amount still owed associated with financing of property insurance policy for one year. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true 8515000 8515 false false 4 false true 9291000 9291 false false The amount still owed associated with financing of property insurance policy for one year. No authoritative reference available. false 47 Dividend to spin off Financing 3 wlt_NonCashDividendRelatedToSpinOff wlt false credit duration monetary Dividend (non-cash) distributed relating to the spin-off of Financing business. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false true 437407000 437407 false false 4 false false 0 0 false false Dividend (non-cash) distributed relating to the spin-off of Financing business. No authoritative reference available. false 48 Acquisition of property, plant and equipment under capital lease and other obligations 3 us-gaap_CapitalExpendituresIncurredButNotYetPaid us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false 4 true true 22587000 22587 false false No definition available. No authoritative reference available. false false 4 45 false Thousands UnKnown UnKnown false true