Asset Retirement Obligations (Tables)

9 Months Ended

Sep. 30, 2017

Asset Retirement Obligation Disclosure

Schedule of changes in carrying amount of asset retirement obligations

	2017		2016
Balance as of January 1,	$	98,166	$	153,155
Accretion expense		5,532		5,641
Revisions to estimated future reclamation cash flows		9,350		(53,769)
Payments		(719)		(1,048)
Balance as of September 30,		112,329		103,979
Less: current portion		(1,118)		(1,400)
Asset retirement obligation, net of current portion	$	111,211	$	102,579