Benefit Plans (Termination And Curtailment Costs Changes For Postretirement Health Care Plans) (Details) (Post-Retirement [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2009
Defined Benefit Plan Disclosure [Line Items]
Termination and curtailment	$ (4)	$ 40
Accrued Postretirement Health Care Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Termination and curtailment	11	40
Prior Service Credit [Member]
Defined Benefit Plan Disclosure [Line Items]
Termination and curtailment	$ (15)

- Definition

The aggregate amount of net gain (loss) recognized in net periodic benefit cost due to settlements and curtailments. Curtailments result from an event that significantly reduces the expected years of future service of present employees or eliminates for a significant number of employees the accrual of defined benefits for some or all of their future services. Settlements result from an irrevocable action that relieves the employer (or the plan) of primary responsibility for a benefit obligation and eliminates significant risks related to the obligation and the assets used to effect the settlement. Examples of transactions that constitute a settlement include (a) making lump-sum cash payments to plan participants in exchange for their rights to receive specified benefits and (b) purchasing nonparticipating annuity contracts to cover vested benefits.

+ References+ Details