Asset Retirement Obligation (Tables)

12 Months Ended

Dec. 31, 2013

Schedule of Change in Asset Retirement Obligation

	(In thousands)	Years Ended December 31,
		2013		2012
Beginning balance		$	56,849	$	51,295
	Adjustment due to change in estimate of related costs		748		3,570
	Accretion of liability		5,106		4,920
	Liabilities settled		(3,323)		(2,936)
Ending balance		$	59,380	$	56,849