Other Long-Term Obligations (Tables)

12 Months Ended

Dec. 31, 2012

Other Long-Term Obligations

Schedule of federal coal lease obligations

At December 31, federal coal lease obligations comprise (in thousands):

	2012		2011
Federal coal lease obligations, current	$	63,191	$	102,198
Federal coal lease obligations, noncurrent		122,928		186,119
Total federal coal lease obligations	$	186,119	$	288,317

Schedule of payments for federal coal lease obligations

As of December 31, we have federal coal lease payments, as follows (in thousands):

						2012				2011
Payment Dates	Annual Payment		Imputed Interest Rate			Carrying Value		Fair Value(1)		Carrying Value		Fair Value
August 1, 2008 - 2012	$	50,160		7.50	%		—		—		46,661		48,867
May 1, 2009 - 2013	$	9,620		8.70	%		8,852		9,532		16,998		18,517
July 1, 2011 - 2015	$	59,545		8.50	%		152,078		171,075		192,892		215,796
September 1, 2011 - 2015	$	9,862		8.50	%		25,189		28,196		31,766		35,293
						$	186,119	$	208,803	$	288,317	$	318,473

(1)

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

Schedule of future payments on federal coal leases

Future payments on federal coal leases are as follows (in millions):

Year Ended December 31,
2013	$	79,027
2014		69,407
2015		69,407
Total		217,841
Less: imputed interest		31,722
Total principal payments		186,119
Less: current portion		63,191
Long-term federal coal leases payable	$	122,928

Schedule of imputed interest

Imputed interest on federal coal leases for the years ended December 31 was as follows (in thousands):

	2012		2011		2010
Imputed interest	$	20,406	$	19,619	$	11,673

Schedule of purchase obligations in connection with the acquisition of land and mineral rights

At December 31, we had the following purchase obligations with parties other than the BLM (in thousands):

	2012	2011
Purchase obligations, total	$2,661	$6,567
Interest rate	6% - 8%	6% - 8%