Dispositions (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended	3 Months Ended		3 Months Ended
	Mar. 31, 2014 Discontinued Operations [Member]	Dec. 31, 2013 Discontinued Operations [Member]	Mar. 31, 2013 Bailey Longwall Shields [Member]	Mar. 31, 2014 Bailey Longwall Shields [Member]	Jun. 30, 2013 Potomac coal reserves [Member]	Jun. 30, 2013 Ryerson Park Lake and Dam [Member]	Apr. 30, 2013 Ryerson Park Lake and Dam [Member] acre
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sale Leaseback Transaction, Net Book Value				$ 75,357
Benefit Obligations Assumed By Murray Energy		2,050,656
Sale Leaseback Transaction, Net Proceeds			71,166
Proceeds from Sale of Property, Plant, and Equipment		825,285			25,000
Gain (Loss) on Sale of Property Plant Equipment		1,035,346	(358)		24,663
Litigation Settlement, Amount						36,000
Restructuring Costs		24,715
Discontinued Operations amount of adjustment to prior period gain on disposal	7,044
Bonus Payment						$ 13,728
Gas and Oil Area, Undeveloped, Gross							506,000