Federal Coal Lease Obligations (Tables)

3 Months Ended

Mar. 31, 2015

Federal Coal Lease Obligations

Schedule of federal coal lease obligations

	March 31,		December 31,
	2015		2014
Federal coal lease obligations, current	$	63,970	$	63,970
Federal coal lease obligations, noncurrent		—		—
Total federal coal lease obligations	$	63,970	$	63,970

Schedule of payments for federal coal lease obligations

					March 31, 2015				December 31, 2014
	Annual		Imputed		Carrying		Fair		Carrying		Fair
Payment Dates	Payment		Interest Rate		Value		Value (1)		Value		Value (1)
July 1, 2015	$	59,545	8.50	%		54,880		59,246		54,880		58,976
September 1, 2015	$	9,862	8.50	%		9,090		9,780		9,090		9,736
					$	63,970	$	69,026	$	63,970	$	68,712

• The fair value of estimates for federal coal lease obligations was determined by discounting the remaining lease payments using the then current estimate of the credit-adjusted, risk-free rate based on our then current credit rating, whichis considered Level 2 in the fair value hierarchy.