ASSET RETIREMENT OBLIGATIONS

3 Months Ended

Mar. 31, 2017

ASSET RETIREMENT OBLIGATIONS [Abstract]

Note 9: Asset Retirement Obligations

Asset retirement obligations (AROs) are legal obligations associated with the retirement of long-lived assets resulting from the acquisition, construction, development and/or normal use of the underlying assets.

Recognition of a liability for an ARO is required in the period in which it is incurred at its estimated fair value. The associated asset retirement costs are capitalized as part of the carrying amount of the underlying asset and depreciated over the estimated useful life of the asset. The liability is accreted through charges to operating expenses. If the ARO is settled for other than the carrying amount of the liability, we recognize a gain or loss on settlement.

We record all AROs for which we have legal obligations for land reclamation at estimated fair value. Essentially all these AROs relate to our underlying land parcels, including both owned properties and mineral leases. For the three month periods ended March 31, we recognized ARO operating costs related to accretion of the liabilities and depreciation of the assets as follows:



	Three Months Ended
	March 31
in thousands	2017	2016
ARO Operating Costs
Accretion	$ 2,882	$ 2,755
Depreciation	1,632	1,693
Total	$ 4,514	$ 4,448

ARO operating costs are reported in cost of revenues. AROs are reported within other noncurrent liabilities in our accompanying Condensed Consolidated Balance Sheets.

Reconciliations of the carrying amounts of our AROs are as follows:



	Three Months Ended
	March 31
in thousands	2017	2016
Asset Retirement Obligations
Balance at beginning of year	$ 223,872	$ 226,594
Liabilities incurred	0	0
Liabilities settled	(4,865)	(4,868)
Accretion expense	2,882	2,755
Revisions, net	4,123	(3,900)
Balance at end of period	$ 226,012	$ 220,581