Fair Value Fair Value Nonrecurring Basis (Details) - USD ($)	3 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Held-for-sale, Not Part of Disposal Group, Other		$ 200,000	$ 5,800,000
Impairment of Long-Lived Assets to be Disposed of		(200,000)	(3,000,000.0)
Assets Held-for-sale, Long Lived, Fair Value Disclosure		0	2,800,000
Long Lived Assets Held and Used Carrying Amount		6,100,000	800,000
Impairment of Long-Lived Assets Held-for-use		(3,600,000)	(300,000)
Long Lived Assets Held and Used Fair Value		$ 2,500,000	500,000
Land [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Held-for-sale, Not Part of Disposal Group, Other			5,800,000
Impairment of Long-Lived Assets to be Disposed of			(3,000,000.0)
Assets Held-for-sale, Long Lived, Fair Value Disclosure			2,800,000
Property, Plant and Equipment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long Lived Assets Held and Used Carrying Amount			800,000
Impairment of Long-Lived Assets Held-for-use			300,000
Long Lived Assets Held and Used Fair Value			$ 500,000
Altavista Bearing Plant [Member] [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long Lived Assets Held and Used Fair Value	$ 2,500,000
Benoni [Member] | Property, Plant and Equipment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long Lived Assets Held and Used Carrying Amount	500,000
Impairment of Long-Lived Assets Held-for-use	500,000
Long Lived Assets Held and Used Fair Value	$ 0