REGULATORY MATTERS (Tables)

6 Months Ended

Jun. 30, 2015

REGULATORY MATTERS [Abstract]

Schedule of Changes in Net Regulatory Asset Balance

	For the three months						For the six months
	ended June 30,						ended June 30,
	2015			2014			2015			2014
	(in millions)
Net regulatory asset balance at beginning of period	$	(6.8	)	$	8.1		$	6.0		$	7.7
Current period (over)/under recovery revenue adjustments		9.6			(3.5	)		0.5			(1.2	)
Amortization of prior year regulatory asset		(0.8	)		(5.8	)		(4.5	)		(7.7	)
Net regulatory asset (liability) balance at end of period	$	2.0		$	(1.2	)	$	2.0		$	(1.2	)