Employee Retirement Plans (Tables)

6 Months Ended

Jun. 30, 2012

Pension cost

Employee retirement plans

Schedule of components of net periodic other postretirement benefit cost

	Three months ended						Six months ended
	June 30, 2012			June 30, 2011			June 30, 2012			June 30, 2011
Component of net periodic pension cost:
Service cost	$	67		$	240		$	134		$	480
Interest cost	370			385			740			770
Expected return on plan assets	(318		)	(339		)	(636		)	(678		)
Amortization of net loss	192			113			384			226
Net periodic pension cost	$	311		$	399		$	622		$	798

Other postretirement benefit cost

Employee retirement plans

Schedule of components of net periodic other postretirement benefit cost

	Three months ended						Six months ended
	June 30, 2012			June 30, 2011			June 30, 2012			June 30, 2011
Components of net periodic other postretirement benefit cost
Service cost	$	70		$	66		$	140		$	131
Interest cost	90			102			180			204
Amortization of net gain	(4		)	(15		)	(8		)	(31		)
Net periodic other postretirement benefit cost	$	156		$	153		$	312		$	304