dei:EntityCentralIndexKey dei:DocumentType us-gaap:LossContingencyAccrualAtCarryingValue us-gaap:LossContingencyAccrualCarryingValuePeriodIncreaseDecrease Amount of nonmonetary gain or loss on recognized transactions foots. us-gaap:NonmonetaryTransactionGainLossRecognizedOnTransfer us-gaap:NonmonetaryTransactionTypeAxis xfi:fact-explicit-dimension-value($v:VARIABLE_Total,QName('http://xbrl.us/us-gaap/2009-01-31','us-gaap:NonmonetaryTransactionTypeAxis')) http://xbrl.org/int/dim/arcrole/domain-member child Amount of nonmonetary barter transactions foots. us-gaap:NonmonetaryTransactionAmountOfBarterTransaction us-gaap:NonmonetaryTransactionTypeAxis xfi:fact-explicit-dimension-value($v:VARIABLE_Total,QName('http://xbrl.us/us-gaap/2009-01-31','us-gaap:NonmonetaryTransactionTypeAxis')) http://xbrl.org/int/dim/arcrole/domain-member child