Asset Retirement Obligations

12 Months Ended

Dec. 31, 2012

Asset Retirement Obligation [Abstract]

Asset retirement obligations

Asset Retirement Obligations

The Company records obligations related to the plugging and abandonment of oil and natural gas wells, decommissioning of certain electric generating facilities, reclamation of certain aggregate properties, special handling and disposal of hazardous materials at certain electric generating facilities, natural gas distribution facilities and buildings, and certain other obligations.

A reconciliation of the Company's liability, which is included in other accrued liabilities and other liabilities on the Consolidated Balance Sheets, for the years ended December 31 was as follows:

	2012			2011
	(In thousands)
Balance at beginning of year	$	98,151		$	95,970
Liabilities incurred	6,523			3,870
Liabilities acquired	—			—
Liabilities settled	(10,472		)	(10,418		)
Accretion expense	4,266			4,466
Revisions in estimates	3,655			3,921
Other	422			342
Balance at end of year	$	102,545		$	98,151

The Company believes that any expenses related to asset retirement obligations at the Company's regulated operations will be recovered in rates over time and, accordingly, defers such expenses as regulatory assets.

The fair value of assets that are legally restricted for purposes of settling asset retirement obligations at December 31, 2012 and 2011, was $5.0 million and $5.7 million, respectively. The legally restricted assets consist primarily of money market funds and are reflected in other assets on the Consolidated Balance Sheets.