Benefit Obligations (Schedule of Company Commitments to Fund Benefit Obligations) (Details) (USD $) In Millions	9 Months Ended
	Sep. 30, 2011
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions to pension plans	$ 133
Expected employer contributions to pension plans in current fiscal year	164
Nonqualified Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions to pension plans	11
Expected employer contributions to pension plans in current fiscal year	15
Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions to pension plans	22
Expected employer contributions to pension plans in current fiscal year	$ 27