Retirement Benefits (Tables)

9 Months Ended

Sep. 30, 2012

Retirement Benefits

Schedule of net periodic benefit pension cost

	Three months ended September 30,
	Pension Benefits						SERP						OPEB
	2012			2011			2012			2011			2012			2011
Service cost	$	1,439		$	1,399		$	23		$	23		$	671		$	566
Interest cost	2,591			2,601			86			46			962			1,096
Expected return on plan assets	(3,080		)	(2,785		)	—			—			(1,018		)	(1,039		)
Amortization of prior service cost (1)	133			133			(2		)	(2		)	(253		)	(253		)
Amortization of net actuarial loss (1)	2,052			1,374			139			43			311			441
Net periodic benefit cost	$	3,135		$	2,722		$	246		$	110		$	673		$	811

	Nine months ended September 30,
	Pension Benefits						SERP						OPEB
	2012			2011			2012			2011			2012			2011
Service cost	$	4,696		$	4,197		$	39		$	70		$	1,801		$	1,699
Interest cost	7,693			7,804			197			137			3,027			3,287
Expected return on plan assets	(9,232		)	(8,354		)	—			—			(3,101		)	(3,118		)
Amortization of prior service cost (1)	398			398			(6		)	(6		)	(758		)	(758		)
Amortization of net actuarial loss (1)	5,952			4,121			291			128			1,246			1,322
Net periodic benefit cost	$	9,507		$	8,166		$	521		$	329		$	2,215		$	2,432

	Twelve months ended September 30,
	Pension Benefits						SERP						OPEB
	2012			2011			2012			2011			2012			2011
Service cost	$	6,094		$	5,418		$	62		$	87		$	2,367		$	2,234
Interest cost	10,295			10,333			243			176			4,123			4,370
Expected return on plan assets	(12,017		)	(10,816		)	—			—			(4,140		)	(4,079		)
Amortization of prior service cost (1)	532			532			(8		)	(8		)	(1,011		)	(1,011		)
Amortization of net actuarial loss (1)	7,325			5,120			334			152			1,687			1,696
Net periodic benefit cost	$	12,229		$	10,587		$	631		$	407		$	3,026		$	3,210

(1) Amounts are amortized from our regulatory asset originally recorded upon recognizing our net pension liability on the balance sheet.