Benefit Plans (Narratives) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Apr. 02, 2011	Mar. 01, 2009	Jan. 01, 2007	Jan. 01, 1993
Defined Benefit Plan Disclosure [Line Items]
Employer Contributions	$ 10,000,000	$ 20,000,000	$ 10,000,000
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	10,000,000
Postretirement Medical Plans, Description of Change, Limit Employer Medical Contributions, Percent							200.00%
Postretirement Medical Plans, Description of Change, Age Limit for Subsidized Retiree Coverage					65
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments			10,200,000
Deferred Compensation Arrangements, Participating Executive Election to Defer, Percent	1.00%
Deferred Compensation Liability, Current and Noncurrent	10,000,000	9,900,000
Defined Benefit Plan, Contributions by Employer, Amount Matched Every One Dollar				0.50
Defined Benefit Plan, Contributions by Employer, Matching Policy Per Dollar				1.00
Defined Benefit Plan, Contributions by Employer, Maximum Limit of Employee Salary, Percent				1.00%
Defined Benefit Plan, Description, Minimum Age of Participant						21
Defined Benefit Plan, Assets, Target Allocations, Current Target of Liability-Hedging Assets Allocation	35.00%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	5.04%
Defined Pension Plan, Basis Points	56
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase	5.22%	5.22%
Defined Benefit Plan, Assmption for Annual Rate Increase of Non-Medicare Covered Benefits, Percent	8.50%
Defined Benefit Plan, Assmption for Annual Rate Decrease of Non-Medicare Covered Benefits in 2019, Percent	5.00%
Defined Benefit Plan, Assmption for Annual Rate Increase of Medicare Covered Benefits, Percent	13.00%
Defined Benefit Plan, Assmption for Annual Rate Decrease of Medicare Covered Benefits in 2027, Percent	5.00%
Defined Benefit Plan, Accumulated Benefit Obligation	220,900,000	190,800,000
401k [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer Contributions	500,000	0	0
RIP [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer Contributions	3,200,000	2,500,000	1,800,000
Supplemental Executive Retirement Nonqualified Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase	3.75%	3.75%
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer Contributions	11,399,000	21,268,000
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments	0	0	0
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	5.04%	5.60%	5.98%
Defined Benefit Plan, Accumulated Benefit Obligation	29,527,000	29,891,000
Defined Benefit Plan, Expected Future Benefit Payments in Year One	16,800,000
Defined Benefit Plan, Expected Future Benefit Payments in Year Two	15,700,000
Defined Benefit Plan, Expected Future Benefit Payments in Year Three	15,400,000
Defined Benefit Plan, Expected Future Benefit Payments in Year Four	14,400,000
Defined Benefit Plan, Expected Future Benefit Payments in Year Five	14,900,000
Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter	74,200,000
Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer Contributions	1,416,000	1,707,000
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments	0	0	10,239,000
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.23%	4.43%	4.94%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase
Defined Benefit Plan, Accumulated Benefit Obligation	(16,420,000)	(16,782,000)
Defined Benefit Plan, Expected Future Benefit Payments in Year One	1,800,000
Defined Benefit Plan, Expected Future Benefit Payments in Year Two	1,600,000
Defined Benefit Plan, Expected Future Benefit Payments in Year Three	1,500,000
Defined Benefit Plan, Expected Future Benefit Payments in Year Four	1,400,000
Defined Benefit Plan, Expected Future Benefit Payments in Year Five	1,200,000
Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter	$ 5,000,000