Fair Value of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2014

Fair Value Disclosures [Abstract]

Fair Value, Assets Measured on Recurring Basis [Table Text Block]

The financial instruments measured at fair value on a recurring basis are summarized below:

	Fair Value Measurements at December 31, 2014						Fair Value Measurements at December 31, 2013
Description	Level 1		Level 2		Level 3		Level 1		Level 2		Level 3
Gas Derivatives	$	—	$	193,069	$	—	$	—	$	65,449	$	—
Murray Energy Guarantees	$	—	$	—	$	1,275	$	—	$	—	$	3,000

Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Table Text Block]