Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2012

Intangible Assets

Amounts recorded as intangible assets along with the balances and accumulated amortization at December 31, 2012 and 2011 are reflected in the table below:

	December 31, 2012			December 31, 2011
	(In thousands)
Contract intangibles	$	89,420		$	89,420
Less accumulated amortization		(18,609	)		(14,256	)
Net book value	$	70,811		$	75,164

	For the years ended December 31,
	2012		2011		2010
	(In thousands)
Total amortization expense on intangible assets	$	4,354	$	9,298	$	10,150

Estimated Amortization Expense

The estimates of amortization expense for the periods as indicated below are based on current mining plans and are subject to revision as those plans change in future periods.

Estimated amortization expense (In thousands)
For year ended December 31, 2013	$	3,818
For year ended December 31, 2014		3,690
For year ended December 31, 2015		3,830
For year ended December 31, 2016		3,830
For year ended December 31, 2017		3,830