1.0.0.3 false Subsequent Event 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 2 NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS 0 wlt_NotesToConsolidatedFinancialsAbstract wlt false na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false No definition available. false 3 Subsequent Event 1 us-gaap_ScheduleOfSubsequentEventsTextBlock us-gaap true na duration string No definition available. false false false false false false false false false 1 false false 0 0 <table style="font-size:10pt; font-family:'Times New Roman',times,serif;"> <tr> <td> NOTE 12Subsequent Event         On October 20, 2009, the Company entered into a swap contract to hedge 1.5 bcf of natural gas, or approximately 24% of forecasted 2010 natural gas sales, at a price of $6.20 per thousand cubic feet. The objective of the hedge is to protect against the variability in expected future cash flows attributed to changes in natural gas prices. This contract is structured as a cash flow hedge that will convert a portion of forecasted sales at floating-rate natural gas prices to a fixed-rate basis and was not entered into for trading purposes. As such, changes in the fair value of the hedge will be recorded as a component of other comprehensive income and reclassified into earnings in the same periods during which the hedged transactions affect earnings.</td></tr></table> NOTE 12Subsequent Event         On October 20, 2009, the Company entered into a swap contract to hedge 1.5 false false No definition available. No authoritative reference available. false false 1 2 false UnKnown UnKnown UnKnown false true