Savings Plans, Pension Plans and Other Postretirement Employee Benefits (Weighted Average Asset Alllocations of the Pension Benefit Plans' Assets) (Details)	Dec. 31, 2012	Dec. 31, 2011
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Actual Plan Asset Allocations	100.00%	100.00%
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Actual Plan Asset Allocations	0.00%	0.00%
Domestic Equity Securities [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Actual Plan Asset Allocations	22.00%	21.00%
Domestic Equity Securities [Member] | Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Actual Plan Asset Allocations	0.00%	0.00%
Debt Securities [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Actual Plan Asset Allocations	36.00%	41.00%
Debt Securities [Member] | Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Actual Plan Asset Allocations	0.00%	0.00%
Global and International Equity Securities [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Actual Plan Asset Allocations	28.00%	24.00%
Global and International Equity Securities [Member] | Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Actual Plan Asset Allocations	0.00%	0.00%
Equity Securities, Other [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Actual Plan Asset Allocations	14.00%	14.00%
Equity Securities, Other [Member] | Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Actual Plan Asset Allocations	0.00%	0.00%