Savings Plans, Pension Plans and Other Postretirement Employee Benefits (Change in Benefit Obligation, Plan Assets and Funded Status for Company-Sponsored Benefit Plans and Obligations) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation	$ 445,535	$ 418,251
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets	345,633	312,158
Amounts recognized in the consolidated balance sheets [Abstract]
Current Liabilities	6,888	8,172
Noncurrent Liabilities	145,047	163,116
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Funded Status of Plan	(99,902)	(106,093)
Amounts recognized in the consolidated balance sheets [Abstract]
Current Liabilities	(1,775)	(1,712)
Noncurrent Liabilities	(98,127)	(104,381)
Net Amount Recognized	(99,902)	(106,093)
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Funded Status of Plan	(52,033)	(65,195)
Amounts recognized in the consolidated balance sheets [Abstract]
Current Liabilities	(5,113)	(6,460)
Noncurrent Liabilities	(46,920)	(58,735)
Net Amount Recognized	(52,033)	(65,195)
Benefit Obligation [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation	418,251	395,086
Service Cost	5,238	4,456
Interest Cost	19,986	21,325
Plan Amendments	510	0
Actuarial Loss (Gain)	38,329	27,916
Medicare Part D Subsidies Received	0	0
Benefits Paid	(36,779)	(30,532)
Benefit Obligation	445,535	418,251
Benefit Obligation [Member] | Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation	65,195	72,619
Service Cost	284	446
Interest Cost	2,478	3,486
Plan Amendments	(6,045)	(5,805)
Actuarial Loss (Gain)	(4,878)	(913)
Medicare Part D Subsidies Received	0	741
Benefits Paid	(5,001)	(5,379)
Benefit Obligation	52,033	65,195
Fair Value of Plan Assets [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefits Paid	(36,779)	(30,532)
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets	312,158	329,064
Actual Return on Plan Assets	46,905	2,500
Contributions by Employer	23,349	11,126
Fair Value of Plan Assets	345,633	312,158
Fair Value of Plan Assets [Member] | Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefits Paid	0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets	0	0
Actual Return on Plan Assets	0	0
Contributions by Employer	0	0
Fair Value of Plan Assets	$ 0	$ 0