Noncontrolling Interest (Details) - USD ($) $ in Thousands		3 Months Ended			9 Months Ended		12 Months Ended
	Oct. 26, 2015	Sep. 30, 2015	Jun. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2012	Dec. 31, 2014
Noncontrolling Interest [Line Items]
Noncontrolling interest, ownership percentage by noncontrolling owners		25.00%			25.00%		25.00%
Cost of acquired entity, cash paid by third party							$ 81,250
Contribution, initial cash call, amount paid by third party							$ 13,600
Maximum PGM production purchase percentage							100.00%
Net income (loss) attributable to noncontrolling interest		$ (151)		$ (313)	$ (11,808)	$ (1,083)
Noncontrolling interest		6,672			6,672			$ 18,480
Impairment charge		0		$ 0	46,772	$ 0
Subsequent Event [Member]
Noncontrolling Interest [Line Items]
Purchase of noncontrolling interest, percent	25.00%
Purchase of noncontrolling interest, total consideration	$ 5,200
Purchase of noncontrolling interest, net of cash acquired	$ 1,000
Additional Paid-in Capital [Member]
Noncontrolling Interest [Line Items]
Issuance of noncontrolling interest							$ 42,500
Expenses incurred for issuance of noncontrolling interest							$ 1,100
Noncontrolling Interest [Member]
Noncontrolling Interest [Line Items]
Impairment charge			$ 11,700
Noncontrolling Interest [Member]
Noncontrolling Interest [Line Items]
Noncontrolling interest		$ 6,700			$ 6,700			$ 18,500