Pension Plans and Other Employee Benefits (Tables)

6 Months Ended

Jun. 30, 2012

Pension Plans and Other Employee Benefits [Abstract]

Components of net periodic benefit costs

	Pension Benefits						Other Benefits
Three Months Ended June 30	2012			2011			2012			2011
Components of net periodic benefit costs	(millions)
Service cost	$	8.8		$	7.8		$	0.8		$	0.8
Interest cost		12.3			12.6			2.0			1.9
Expected return on plan assets		(10.7	)		(9.7	)		(0.4	)		(0.5	)
Prior service cost		1.1			1.2			1.8			1.8
Recognized net actuarial (gain) loss		11.2			9.5			-			(0.2	)
Transition obligation		-			-			0.2			0.4
Settlement charge		-			0.2			-			-
Net periodic benefit costs before
regulatory adjustment		22.7			21.6			4.4			4.2
Regulatory adjustment		(3.8	)		(5.9	)		0.3			0.1
Net periodic benefit costs	$	18.9		$	15.7		$	4.7		$	4.3

	Pension Benefits						Other Benefits
Year to Date June 30	2012			2011			2012			2011
Components of net periodic benefit costs	(millions)
Service cost	$	17.7		$	15.6		$	1.6		$	1.6
Interest cost		24.5			25.1			3.9			3.9
Expected return on plan assets		(21.4	)		(19.3	)		(0.9	)		(0.9	)
Prior service cost		2.2			2.3			3.6			3.6
Recognized net actuarial (gain) loss		22.3			19.2			-			(0.3	)
Transition obligation		-			-			0.5			0.7
Settlement charge		-			0.2			-			-
Net periodic benefit costs before
regulatory adjustment		45.3			43.1			8.7			8.6
Regulatory adjustment		(7.7	)		(12.3	)		0.7			0.3
Net periodic benefit costs	$	37.6		$	30.8		$	9.4		$	8.9