Pension and Other Postretirement Benefits Net Periodic Benefit Cost (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Service Cost	$ 5,554	$ 4,123	$ 16,661	$ 12,372
Defined Benefit Plan, Interest Cost	6,224	5,671	18,672	17,013
Defined Benefit Plan, Expected Return on Plan Assets	(5,918)	(5,471)	(17,753)	(16,413)
Defined Benefit Plan, Amortization of Gains (Losses)	5,279	3,526	15,837	10,578
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	346	352	1,036	1,054
Defined Benefit Plan, Net Periodic Benefit Cost	11,485	8,201	34,453	24,604
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Service Cost	584	535	1,752	1,606
Defined Benefit Plan, Interest Cost	838	920	2,516	2,759
Defined Benefit Plan, Expected Return on Plan Assets	0	0	0	0
Defined Benefit Plan, Amortization of Gains (Losses)	430	493	1,290	1,478
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	(546)	(546)	(1,636)	(1,636)
Defined Benefit Plan, Net Periodic Benefit Cost	$ 1,306	$ 1,402	$ 3,922	$ 4,207