Contingencies Contingencies (MSA Term Sheet Agreement) (Narrative) (Details) (USD $)	0 Months Ended	12 Months Ended
	Dec. 17, 2012	Dec. 31, 2012
Loss Contingencies [Line Items]
Number of States Joining Term Sheet	17
Percentage of Signatory States Allocable Share of OPM Aggregate 2003-2012 NPM Adjustments Reduction of Future MSA Payments		46.00%
Affiliate Share of Future MSA Payment Reductions		28.00%
Affiliate Approximate Amount of Future MSA Payment Reductions		$ 450,000,000
Disputed Payment Account (DPA) Balance		4,000,000,000
Affiliate Payments to DPA Account		458,000,000
Amount of Affiliate Funds Released from DPA to Signatory States		$ 190,000,000