Discontinued Operations Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Disposal Group, Including Discontinued Operation, Assets, Current	$ 83	$ 81,105
Disposal Group, Including Discontinued Operation, Property, Plant and Equipment	0	936,671
Disposal Group, Including Discontinued Operation, Liabilities, Current	6,050	51,514
Disposal Group, Including Discontinued Operation, Liabilities, Noncurrent	0	107,988
Disposal Group, including discontinued operations, reclamation, non-current	0	34,126
Disposal Group, Including Discontinued Operation, Liabilities	0	5,001
Buchanan and Other Assets [Member]
Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net	83	49,125
Disposal Group, Including Discontinued Operation, Inventory	0	30,646
Disposal Group, Including Discontinued Operation, Prepaid and Other Assets	0	970
Disposal Group, Including Discontinued Operation, Prepaid and Other Assets, Current	0	364
Disposal Group, Including Discontinued Operation, Assets, Current	83	81,105
Disposal Group, Including Discontinued Operation, Property, Plant and Equipment	0	936,671
Disposal Group, Including Discontinued Operation, Other Assets, Noncurrent	0	4,044
Disposal Group, Including Discontinued Operation, Assets	83	1,021,820
Disposal Group, Including Discontinued Operation, Accounts Payable	36	20,786
Disposal Group, Including Discontinued Operation, Liabilities, Current	6,014	30,728
Disposal Group, Including Discontinued Operation, Liabilities, Noncurrent	0	5,001
Disposal Group, including discontinued operations, Pneumoconiosis Benefits	0	1,129
Disposal Group, including discontinued operations, Mine Closing non current	0	71,941
Disposal Group, Including Discontinued Operation, Other Liabilities, Noncurrent	0	792
Disposal Group, Including Discontinued Operation, Liabilities	$ 6,050	$ 164,503