Asset Impairment	9 Months Ended
Sep. 30, 2015
Asset Impairment Charges [Abstract]
Asset Impairment	ASSET IMPAIRMENT In accordance with the Financial Accounting Standards Board (FASB) Accounting Standards Codification 360, Property Plant and Equipment (ASC 360-10), the Company reviews and evaluates its long-lived assets for impairment when events and changes in circumstances indicate that the related carrying amounts of such assets may not be recoverable and may exceed their fair value. For purposes of determining impairment, assets are grouped at the lowest level for which identifiable cash flows (including estimated future cash flows from non-operating properties) are largely independent of the cash flows of other groups of assets and liabilities. In the third quarter of 2015, the Company recorded an increase of $1.1 million in estimated reclamation costs at the Stillwater Mine, related to the Benbow portal. As a result of inquiries relating to the Marathon project received during the second quarter of 2015 the Company concluded that there was evidence to suggest that there had been a significant decrease in the fair value of the Marathon mineral properties. Accordingly, the Company performed an analysis that indicated the carrying value of the Marathon mineral properties exceeded its recoverable amount at June 30, 2015. The Company undertook an assessment of the fair value of its Marathon mineral properties, which included the examination of recent comparable transactions. During the second quarter of 2015, the Company recorded an impairment charge of $46.8 million (before-tax) against the carrying value of the Marathon mineral properties in Canada, reducing its carrying value to an estimated fair value of $8.6 million. The Company determined at December 31, 2014, that certain real estate properties owned by the Company in the town of Marathon that previously were associated with the Marathon project should be segregated and considered separately for impairment. The Company obtained an estimate of fair value from a real estate firm in the Marathon area and impaired those properties by approximately $0.5 million at December 31, 2014.

ASSET IMPAIRMENT

In accordance with the Financial Accounting Standards Board (FASB) Accounting Standards Codification 360, Property Plant and Equipment (ASC 360-10), the Company reviews and evaluates its long-lived assets for impairment when events and changes in circumstances indicate that the related carrying amounts of such assets may not be recoverable and may exceed their fair value. For purposes of determining impairment, assets are grouped at the lowest level for which identifiable cash flows (including estimated future cash flows from non-operating properties) are largely independent of the cash flows of other groups of assets and liabilities.

In the third quarter of 2015, the Company recorded an increase of $1.1 million in estimated reclamation costs at the Stillwater Mine, related to the Benbow portal.

As a result of inquiries relating to the Marathon project received during the second quarter of 2015 the Company concluded that there was evidence to suggest that there had been a significant decrease in the fair value of the Marathon mineral properties. Accordingly, the Company performed an analysis that indicated the carrying value of the Marathon mineral properties exceeded its recoverable amount at June 30, 2015. The Company undertook an assessment of the fair value of its Marathon mineral properties, which included the examination of recent comparable transactions. During the second quarter of 2015, the Company recorded an impairment charge of $46.8 million (before-tax) against the carrying value of the Marathon mineral properties in Canada, reducing its carrying value to an estimated fair value of $8.6 million.

The Company determined at December 31, 2014, that certain real estate properties owned by the Company in the town of Marathon that previously were associated with the Marathon project should be segregated and considered separately for impairment. The Company obtained an estimate of fair value from a real estate firm in the Marathon area and impaired those properties by approximately $0.5 million at December 31, 2014.