Noncontrolling Interest (Details) (USD $)	1 Months Ended	6 Months Ended		3 Months Ended	6 Months Ended
	Mar. 28, 2012	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2012 Additional Paid-in Capital [Member]	Jun. 30, 2012 Additional Paid-in Capital [Member]
Noncontrolling Interest [Line Items]
Percentage of interest acquired	25.00%
Cash paid for business acquisition	$ 81,250,000
Amount for first venture cash call	13,600,000
Maximum PGM production purchase percentage	100.00%
Transaction closing date	April 10, 2012
Transaction costs included within equity		1,100,000
Noncontrolling interest		52,019,000	0
Issuance of noncontrolling interest					42,500,000
Expenses incurred for issuance of noncontrolling interest				$ 300,000	$ 1,100,000