Property, Plant And Equipment (Schedule Of Capital Expenditures) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Property, Plant and Equipment [Line Items]
Total capital outlay		$ 112,748	$ 101,940	$ 50,263
Acquired by capital lease transactions	(700)	(677)	0	0
Capital expenditures		112,071	101,940	50,263
Stillwater Mine [Member]
Property, Plant and Equipment [Line Items]
Total capital outlay		86,541	69,168	34,093
East Boulder Mine [Member]
Property, Plant and Equipment [Line Items]
Total capital outlay		10,443	18,888	6,513
Marathon Project [Member]
Property, Plant and Equipment [Line Items]
Total capital outlay		8,319	13,470	45
Altar Property [Member]
Property, Plant and Equipment [Line Items]
Total capital outlay		18	63	0
Other Mine [Member]
Property, Plant and Equipment [Line Items]
Total capital outlay		$ 7,427	$ 351	$ 9,612