Regulatory Assets and Liabilities

12 Months Ended

Dec. 31, 2012

Regulatory Assets and Liabilities Disclosure [Abstract]

Regulatory Assets and Liabilities

REGULATORY ASSETS AND LIABILITIES

The following table details regulatory assets and liabilities on the consolidated balance sheets:

(in thousands)	December 31, 2012				December 31, 2011
	Current		Noncurrent		Current		Noncurrent
Regulatory assets:
Pension and postretirement assets	$	170	$	90,708	$	170	$	77,587
Accretion and depreciation for asset retirement obligation	—		16,536		—		13,981
Risk management activities	2,593		—		56,804		3,070
Rate recovery of asset removal costs, net	—		3,322		—		994
Gas supply adjustment	42,726		—		—		—
Other	26		—		169		1
Total regulatory assets	$	45,515	$	110,566	$	57,143	$	95,633
Regulatory liabilities:
RSE adjustment	$	1,740	$	—	$	2,931	$	—
Unbilled service margin	25,078		—		22,419		—
Postretirement liabilities	—		1,237		—		—
Gas supply adjustment	—		—		12,626		—
Refundable negative salvage	18,265		53,467		20,269		65,646
Asset retirement obligation	—		24,930		—		20,785
Other	33		770		34		803
Total regulatory liabilities	$	45,116	$	80,404	$	58,279	$	87,234

As described in Note 2, Regulatory Matters, Alagasco's rates are established under the RSE rate-setting process and are based on average equity for the period. Alagasco's rates are not adjusted to exclude a return on its investment in regulatory assets during the recovery period.