Components of net periodic benefit cost

6 Months Ended

Jun. 30, 2012

Components of net periodic benefit cost [Abstract]

Components of net periodic benefit cost

Components of net periodic benefit cost

	Pension Benefits
	Three months ended June 30,						Six months ended June 30,
	2012			2011			2012			2011
Service cost	$	506		$	709		$	1,401		$	1,566
Interest cost	1,606			1,808			3,436			3,488
Expected return on plan assets	(1,782		)	(1,776		)	(3,482		)	(3,315		)
Amortization of prior service cost	34			34			69			69
Amortization of net loss	1,133			449			1,821			931
Net periodic benefit cost	$	1,497		$	1,224		$	3,245		$	2,739

	Other Postretirement Benefits
	Three months ended June 30,						Six months ended June 30,
	2012			2011			2012			2011
Service cost	$	370		$	475		$	895		$	834
Interest cost	1,271			1,478			2,757			2,864
Expected return on plan assets	—			—			—			—
Amortization of prior service cost (1)	(1,065		)	(15,534		)	(2,125		)	(30,689		)
Amortization of net loss	1,808			6,546			3,304			12,349
Net periodic benefit cost	$	2,384		$	(7,035	)	$	4,831		$	(14,642	)

(1) Plan amendments made in November 2010 resulted in a reduction in OPEB liability and a credit to accumulated other comprehensive loss. The resulting prior service benefit and actuarial losses were amortized ratably into income over the period November 1, 2010 to June 30, 2011 at which time the CAWV OPEB plan terminated.

Employer contributions

During the six months ended June 30, 2012, we have made contributions of approximately $5,458 to the qualified defined benefit plans we sponsor.