Assets Retirement Obligations (Tables)

6 Months Ended

Jun. 30, 2015

Asset Retirement Obligation Disclosure [Abstract]

Summary of Asset Retirement Obligation

The following table summarizes the changes in the reserve for future restoration and reclamation costs on the balance sheet:

	June 30, 2015			December 31, 2014
	(thousands of dollars)
Balance, beginning of period	$	4,196		$	3,834
Additions, changes in estimates and other		-			136
Liabilities settled		(88	)		(199	)
Accretion expense		225			425
Balance, end of period		4,333			4,196
Less: Current portion		(144	)		(196	)
Non-current Portion	$	4,189		$	4,000