Pension and Other Postretirement Benefits (Details) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost				$ 1,172
Interest cost				2,282
Recognized actuarial loss				195
Amortization of transition obligation				328
Amortization of prior service cost				(102)
Total net pension and other postretirement costs				3,875
Less: Discontinued operations				1,364
Total net pension and postretirement costs from Continuing operations				2,511
Contribution to pension and other postretirement benefit plans during period			37,200
Expected additional contributions to pension and other postretirement benefit plans for the year	18,300		18,300
Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	3,107	3,969	6,181	7,894
Interest cost	7,718	7,737	15,350	15,389
Expected return on plan assets	(8,352)	(7,611)	(16,613)	(15,138)
Recognized actuarial loss	5,774	5,318	11,515	10,621
Amortization of prior service cost	(1,665)	(1,665)	(3,312)	(3,312)
Total net pension and other postretirement costs	6,582	7,748	13,121	15,454
Less: Discontinued operations	2,247	3,809	4,595	7,516
Total net pension and postretirement costs from Continuing operations	4,335	3,939	8,526	7,938
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	541	589	1,076
Interest cost	1,053	1,147	2,094
Recognized actuarial loss	73	98	146
Amortization of transition obligation	165	165	328
Amortization of prior service cost	(51)	(51)	(101)
Total net pension and other postretirement costs	1,781	1,948	3,543
Less: Discontinued operations	599	703	1,220
Total net pension and postretirement costs from Continuing operations	$ 1,182	$ 1,245	$ 2,323