Income Taxes	9 Months Ended
Sep. 30, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes: The Company’s effective income tax rate differs from the U.S. statutory federal income tax rate primarily due to U.S. statutory depletion, state income taxes (net of federal tax benefit), foreign income tax rate differentials, foreign mining taxes, domestic manufacturing deductions, and interest expense recognition differences for book and tax purposes. The Company’s effective rate is impacted by permanent tax deductions which have a less favorable impact as pretax income increases. At both September 30, 2015 and December 31, 2014, the Company had approximately $3.8 million of gross foreign federal net operating loss (“NOL”) carryforwards that have no expiration date. In addition, the Company had $8.0 million and $2.3 million as of September 30, 2015 and December 31, 2014, respectively, of gross foreign federal NOL carryforwards which expire beginning in 2033 and $1.0 million and $0.3 million as of September 30, 2015 and December 31, 2014, respectively, of tax-effected state NOL carryforwards which expire beginning in 2033. In the future, if the Company determines, based on the existence of sufficient evidence, that it should realize more or less of its deferred tax assets, an adjustment to any existing valuation allowance will be made in the period such determination is made. Canadian provincial tax authorities have challenged tax positions claimed by one of the Company’s Canadian subsidiaries and have issued tax reassessments for years 2002-2009. The reassessments are a result of ongoing audits and total approximately $80 million, including interest through September 30, 2015. The Company disputes these reassessments and plans to continue to work with the appropriate authorities in Canada to resolve the dispute. There is a reasonable possibility that the ultimate resolution of this dispute, and any related disputes for other open tax years, may be materially higher or lower than the amounts the Company has reserved for such disputes. In connection with this dispute, local regulations require the Company to post security with the tax authority until the dispute is resolved. The Company and the tax authority have agreed that it will post collateral in the form of a $50 million performance bond. The Company has paid approximately $28 million (most of which is recorded in other assets in the consolidated balance sheets) with the remaining balance to be paid after 2015. In addition, Canadian federal and provincial taxing authorities have reassessed the Company for years 2004-2006 which have been previously settled by agreement among the Company, the Canadian federal taxing authority and the U.S. federal taxing authority. The Company has fully complied with the agreement since entering into it and it believes this action is highly unusual. The Company is seeking to enforce the agreement which provided the basis upon which the returns were previously filed and settled. The total amount of the reassessments, including penalties and interest through September 30, 2015, related to this matter is approximately $89 million. The Company has agreed to post collateral in the form of an approximately $18 million performance bond and $36 million in the form of a bank letter guarantee which is necessary to proceed with future appeals or litigation. The Company received Canadian income tax reassessments for years 2007-2008. The total amount of the reassessments, including penalties and interest through September 30, 2015, related to this matter is approximately $31 million. The Company does not agree with these adjustments and has filed for assistance from the tax jurisdictions for relief from the impact of double taxation as available in the tax treaty between the U.S. and Canada. The Company has filed protective Notices of Objection and has agreed to post collateral of an approximately $10 million performance bond and $10 million in the form of a bank letter guarantee which is necessary to proceed with future appeals or litigation. Although the outcome of examinations by taxing authorities is uncertain, the Company believes it has adequately reserved for this matter. The Company will be required by the same local regulations to provide security for additional interest on the above disputed amounts and for any future reassessments issued by these Canadian tax authorities in the form of cash, letters of credit, performance bonds, asset liens or other arrangements agreeable with the tax authorities until the dispute is resolved. The Company expects that the ultimate outcome of these matters will not have a material impact on its results of operations or financial condition. However, the Company can provide no assurance as to the ultimate outcome of these matters and the impact could be material if they are not resolved in the Company’s favor. As of September 30, 2015, the amount reserved related to these reassessments was immaterial to the Company’s consolidated financial statements. Additionally, the Company has other uncertain tax positions as well as assessments and disputed positions with taxing authorities in its various jurisdictions.

Income Taxes:

The Company’s effective income tax rate differs from the U.S. statutory federal income tax rate primarily due to U.S. statutory depletion, state income taxes (net of federal tax benefit), foreign income tax rate differentials, foreign mining taxes, domestic manufacturing deductions, and interest expense recognition differences for book and tax purposes. The Company’s effective rate is impacted by permanent tax deductions which have a less favorable impact as pretax income increases.

At both September 30, 2015 and December 31, 2014, the Company had approximately $3.8 million of gross foreign federal net operating loss (“NOL”) carryforwards that have no expiration date. In addition, the Company had $8.0 million and $2.3 million as of September 30, 2015 and December 31, 2014, respectively, of gross foreign federal NOL carryforwards which expire beginning in 2033 and $1.0 million and $0.3 million as of September 30, 2015 and December 31, 2014, respectively, of tax-effected state NOL carryforwards which expire beginning in 2033. In the future, if the Company determines, based on the existence of sufficient evidence, that it should realize more or less of its deferred tax assets, an adjustment to any existing valuation allowance will be made in the period such determination is made.

Canadian provincial tax authorities have challenged tax positions claimed by one of the Company’s Canadian subsidiaries and have issued tax reassessments for years 2002-2009. The reassessments are a result of ongoing audits and total approximately $80 million, including interest through September 30, 2015. The Company disputes these reassessments and plans to continue to work with the appropriate authorities in Canada to resolve the dispute. There is a reasonable possibility that the ultimate resolution of this dispute, and any related disputes for other open tax years, may be materially higher or lower than the amounts the Company has reserved for such disputes. In connection with this dispute, local regulations require the Company to post security with the tax authority until the dispute is resolved. The Company and the tax authority have agreed that it will post collateral in the form of a $50 million performance bond. The Company has paid approximately $28 million (most of which is recorded in other assets in the consolidated balance sheets) with the remaining balance to be paid after 2015.

In addition, Canadian federal and provincial taxing authorities have reassessed the Company for years 2004-2006 which have been previously settled by agreement among the Company, the Canadian federal taxing authority and the U.S. federal taxing authority. The Company has fully complied with the agreement since entering into it and it believes this action is highly unusual. The Company is seeking to enforce the agreement which provided the basis upon which the returns were previously filed and settled. The total amount of the reassessments, including penalties and interest through September 30, 2015, related to this matter is approximately $89 million. The Company has agreed to post collateral in the form of an approximately $18 million performance bond and $36 million in the form of a bank letter guarantee which is necessary to proceed with future appeals or litigation.

The Company received Canadian income tax reassessments for years 2007-2008. The total amount of the reassessments, including penalties and interest through September 30, 2015, related to this matter is approximately $31 million. The Company does not agree with these adjustments and has filed for assistance from the tax jurisdictions for relief from the impact of double taxation as available in the tax treaty between the U.S. and Canada. The Company has filed protective Notices of Objection and has agreed to post collateral of an approximately $10 million performance bond and $10 million in the form of a bank letter guarantee which is necessary to proceed with future appeals or litigation. Although the outcome of examinations by taxing authorities is uncertain, the Company believes it has adequately reserved for this matter.

The Company will be required by the same local regulations to provide security for additional interest on the above disputed amounts and for any future reassessments issued by these Canadian tax authorities in the form of cash, letters of credit, performance bonds, asset liens or other arrangements agreeable with the tax authorities until the dispute is resolved.

The Company expects that the ultimate outcome of these matters will not have a material impact on its results of operations or financial condition. However, the Company can provide no assurance as to the ultimate outcome of these matters and the impact could be material if they are not resolved in the Company’s favor. As of September 30, 2015, the amount reserved related to these reassessments was immaterial to the Company’s consolidated financial statements.

Additionally, the Company has other uncertain tax positions as well as assessments and disputed positions with taxing authorities in its various jurisdictions.