Retirement Benefits (Tables)

6 Months Ended

Jun. 30, 2012

Retirement Benefits

Schedule of net periodic benefit pension cost

	Three months ended June 30,
	Pension Benefits						SERP						OPEB
	2012			2011			2012			2011			2012			2011
Service cost	$	1,628		$	1,404		$	7		$	27		$	565		$	507
Interest cost	2,551			2,612			56			51			1,032			1,062
Expected return on plan assets	(3,076		)	(2,889		)	—			—			(1,041		)	(1,028		)
Amortization of prior service cost (1)	133			133			(2		)	(2		)	(253		)	(253		)
Amortization of net actuarial loss (1)	1,950			1,395			76			52			468			381
Net periodic benefit cost	$	3,186		$	2,655		$	137		$	128		$	771		$	669

	Six months ended June 30,
	Pension Benefits						SERP						OPEB
	2012			2011			2012			2011			2012			2011
Service cost	$	3,256		$	2,798		$	15		$	47		$	1,129		$	1,133
Interest cost	5,102			5,203			111			91			2,065			2,192
Expected return on plan assets	(6,151		)	(5,569		)	—			—			(2,083		)	(2,078		)
Amortization of prior service cost (1)	266			266			(4		)	(4		)	(505		)	(505		)
Amortization of net actuarial loss (1)	3,899			2,747			153			85			935			881
Net periodic benefit cost	$	6,372		$	5,445		$	275		$	219		$	1,541		$	1,623

	Twelve months ended June 30,
	Pension Benefits						SERP						OPEB
	2012			2011			2012			2011			2012			2011
Service cost	$	6,054		$	5,139		$	62		$	83		$	2,262		$	2,253
Interest cost	10,305			10,218			203			166			4,257			4,396
Expected return on plan assets	(11,721		)	(10,450		)	—			—			(4,161		)	(3,990		)
Amortization of prior service cost (1)	532			531			(8		)	(8		)	(1,011		)	(1,011		)
Amortization of net actuarial loss (1)	6,647			4,676			238			118			1,816			1,691
Net periodic benefit cost	$	11,817		$	10,114		$	495		$	359		$	3,163		$	3,339

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