Retirement and Postretirement Benefits Other than Pension Plans (Tables)

3 Months Ended

Mar. 31, 2012

Defined Benefit Plan Disclosure [Line Items]

Net periodic pension and postretirement benefit expense

	Three months ended March 31,
	2012			2011
Interest cost	$	1,087		$	1,208
Expected return on plan assets		(1,173	)		(1,333	)
Amortization of net actuarial loss		1,170			619
Total net periodic pension expense	$	1,084		$	494

Other Postretirement Benefit Plans, Defined Benefit [Member]

Defined Benefit Plan Disclosure [Line Items]

Net periodic pension and postretirement benefit expense

	Three months ended March 31,
	2012			2011
Service cost	$	14		$	14
Interest cost		254			258
Amortization of net actuarial loss		176			—
Amortization of prior service credit		(108	)		—
Amortization of curtailment gain		(22	)		(61	)
Total net postretirement benefit expense	$	314		$	211