Income Taxes	6 Months Ended
Jun. 30, 2014
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company's tax expense of $4.0 million and tax benefit of $184.7 million for the three months ended June 30, 2014 and 2013, respectively, include remeasurement benefit of $1.3 million and $37.1 million related to foreign tax accounts, respectively. The Company's tax benefit of $48.5 million and $181.0 million for the six months ended June 30, 2014 and 2013, respectively, include remeasurement benefit of $2.7 million and $35.5 million related to foreign tax accounts, respectively. The effective tax rate before remeasurement is based on the Company's estimated full year effective tax rate made up of the expected statutory tax expense more than offset by reductions from percentage depletion, foreign rate differential and Australian minerals resource rent tax. For the three and six months ended June 30, 2014, the Company recorded a valuation allowance on certain Australian deferred tax assets not considered more likely than not to be realized amounting to $75.7 million and $124.7 million, respectively. For the three months ended June 30, 2013, the Company released a portion of its valuation allowance on U.S. capital loss carryforwards amounting to $25.5 million due to a change in expected realization upon sale of non-strategic U.S. coal reserves and surface lands. During the three and six months ended June 30, 2014, the Company decreased its net unrecognized tax benefits, interest and penalties by $19.5 million and $48.4 million, respectively, due to amended returns filed and settlement of intercompany financing transactions on the 2004 through 2012 Australian Taxation Office (ATO) audit. During the six months ended June 30, 2014, the U.S. Internal Revenue Service (IRS) added the 2011 through 2013 tax years to the 2009 through 2010 audit due to amended returns filed for capital and net operating loss carrybacks. The Company believes during the next twelve months it is reasonably possible for a $25.0 million decrease in its net unrecognized tax benefits due to potential audit settlements.

Income Taxes

6 Months Ended

Jun. 30, 2014

The Company's tax expense of $4.0 million and tax benefit of $184.7 million for the three months ended June 30, 2014 and 2013, respectively, include remeasurement benefit of $1.3 million and $37.1 million related to foreign tax accounts, respectively. The Company's tax benefit of $48.5 million and $181.0 million for the six months ended June 30, 2014 and 2013, respectively, include remeasurement benefit of $2.7 million and $35.5 million related to foreign tax accounts, respectively. The effective tax rate before remeasurement is based on the Company's estimated full year effective tax rate made up of the expected statutory tax expense more than offset by reductions from percentage depletion, foreign rate differential and Australian minerals resource rent tax. For the three and six months ended June 30, 2014, the Company recorded a valuation allowance on certain Australian deferred tax assets not considered more likely than not to be realized amounting to $75.7 million and $124.7 million, respectively. For the three months ended June 30, 2013, the Company released a portion of its valuation allowance on U.S. capital loss carryforwards amounting to $25.5 million due to a change in expected realization upon sale of non-strategic U.S. coal reserves and surface lands.

During the three and six months ended June 30, 2014, the Company decreased its net unrecognized tax benefits, interest and penalties by $19.5 million and $48.4 million, respectively, due to amended returns filed and settlement of intercompany financing transactions on the 2004 through 2012 Australian Taxation Office (ATO) audit. During the six months ended June 30, 2014, the U.S. Internal Revenue Service (IRS) added the 2011 through 2013 tax years to the 2009 through 2010 audit due to amended returns filed for capital and net operating loss carrybacks. The Company believes during the next twelve months it is reasonably possible for a $25.0 million decrease in its net unrecognized tax benefits due to potential audit settlements.