New And Significant Accounting Policies (Reclassifications Out Of Accumulated Other Comprehensive Income) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance (net of total income tax of $101)	$ (101)
Other comprehensive income before reclassifications (net of total income tax of $9)	(13)
Amortization of prior service cost (net of income tax of $5)	6	[1]
Amortization of actuarial gains (losses) (net of income tax of $11)	17	[1]
Net current period other comprehensive income	10
Ending balance (net of total income tax of $94)	(91)
Pension and Other Postretirement Benefit Plans [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance (net of total income tax of $101)	(105)
Other comprehensive income before reclassifications (net of total income tax of $9)	(19)
Amortization of prior service cost (net of income tax of $5)	6	[1]
Amortization of actuarial gains (losses) (net of income tax of $11)	17	[1]
Net current period other comprehensive income	4
Ending balance (net of total income tax of $94)	(101)
Other [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance (net of total income tax of $101)	4
Other comprehensive income before reclassifications (net of total income tax of $9)	6
Amortization of prior service cost (net of income tax of $5)	0	[1]
Amortization of actuarial gains (losses) (net of income tax of $11)	0	[1]
Net current period other comprehensive income	6
Ending balance (net of total income tax of $94)	$ 10

[1] These other comprehensive income components are included in the computation of net periodic pension and other postretirement costs. (See the Pension and Other Postretirement Benefits table above for additional details.)