Noncontrolling Interest (Details) (USD $)	1 Months Ended	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2013	Dec. 31, 2012
Noncontrolling Interest [Line Items]
Maximum PGM production purchase percentage		100.00%
Transaction closing date	April, 2012
Noncontrolling interest		$ 51,482,000	$ 51,761,000
Additional Paid-in Capital [Member]
Noncontrolling Interest [Line Items]
Issuance of noncontrolling interest	42,500,000
Expenses incurred for issuance of noncontrolling interest	1,100,000
Equity [Member]
Noncontrolling Interest [Line Items]
Transaction costs included within equity	1,100,000
Noncontrolling Interest [Member]
Noncontrolling Interest [Line Items]
Noncontrolling interest		51,482,000
Stillwater Canada, Inc. [Member]
Noncontrolling Interest [Line Items]
Noncontrolling interest, ownership percentage by noncontrolling owners	25.00%	25.00%
Cost of acquired entity, cash paid by third party	81,250,000
Contribution, initial cash call, amount paid by third party	13,600,000