Regulatory Assets and Liabilities

3 Months Ended

Mar. 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 balance sheets:

(in thousands)	March 31, 2012				December 31, 2011
	Current		Noncurrent		Current		Noncurrent
Regulatory assets:
Pension and postretirement assets	$	170	$	76,165	$	170	$	77,587
Accretion and depreciation for asset retirement obligation	—		14,282		—		13,981
Risk management activities	47,885		—		56,804		3,070
Asset removal costs, net	—		698		—		994
Gas supply adjustment	6,615		333		—		—
Other	120		—		169		1
Total regulatory assets	$	54,790	$	91,478	$	57,143	$	95,633
Regulatory liabilities:
RSE adjustment	$	507	$	—	$	2,931	$	—
Unbilled service margin	7,595		—		22,419		—
Gas supply adjustment	—		—		12,626		—
Refundable negative salvage	21,914		52,333		20,269		65,646
Asset retirement obligation	—		21,031		—		20,785
Other	33		795		34		803
Total regulatory liabilities	$	30,049	$	74,159	$	58,279	$	87,234