REGULATORY ASSETS AND LIABILITIES (Tables)

9 Months Ended

Sep. 30, 2014

Regulated Operations [Abstract]

Regulatory Assets

The following regulatory assets and regulatory liabilities were reflected in the Company's Balance Sheets and also included below:

	September 30, 2014				December 31, 2013
($ Millions)	Current		Noncurrent		Current		Noncurrent
Regulatory assets:
Postretirement assets	$	6.4	$	66.1	$	0.3	$	58.2
Accretion and depreciation for asset retirement obligation	—		18.3		—		18.0
Rate recovery of asset removal costs, net	—		2.8		—		4.7
Enhanced stability reserve	—		3.4		—		4.0
Gas supply adjustment	—		—		2.5		—
RSE adjustment	2.4		—		—		—
Total regulatory assets	$	8.8	$	90.6	$	2.8	$	84.9
Regulatory liabilities:
RSE adjustment	$	19.8	$	—	$	4.7	$	—
Unbilled service margin	5.2		—		28.5		—
Postretirement liabilities	2.3		26.2		—		26.2
Refundable negative salvage	13.4		26.8		15.8		39.7
Gas supply adjustment	22.4		—		—		—
Other	—		0.7		—		0.7
Total regulatory liabilities	$	63.1	$	53.7	$	49.0	$	66.6

Regulatory Liabilities

The following regulatory assets and regulatory liabilities were reflected in the Company's Balance Sheets and also included below:

	September 30, 2014				December 31, 2013
($ Millions)	Current		Noncurrent		Current		Noncurrent
Regulatory assets:
Postretirement assets	$	6.4	$	66.1	$	0.3	$	58.2
Accretion and depreciation for asset retirement obligation	—		18.3		—		18.0
Rate recovery of asset removal costs, net	—		2.8		—		4.7
Enhanced stability reserve	—		3.4		—		4.0
Gas supply adjustment	—		—		2.5		—
RSE adjustment	2.4		—		—		—
Total regulatory assets	$	8.8	$	90.6	$	2.8	$	84.9
Regulatory liabilities:
RSE adjustment	$	19.8	$	—	$	4.7	$	—
Unbilled service margin	5.2		—		28.5		—
Postretirement liabilities	2.3		26.2		—		26.2
Refundable negative salvage	13.4		26.8		15.8		39.7
Gas supply adjustment	22.4		—		—		—
Other	—		0.7		—		0.7
Total regulatory liabilities	$	63.1	$	53.7	$	49.0	$	66.6