Benefit Obligations (Schedule of Company Commitments to Fund Benefit Obligations) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013
Cash Contributions to Defined Benefit Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Commitments to fund benefit obligations	$ 16
Commitments to fund benefit obligations, expected	30
Benefit Payments to Nonqualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Commitments to fund benefit obligations	11
Commitments to fund benefit obligations, expected	22
Benefit Payments to Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Commitments to fund benefit obligations	6
Commitments to fund benefit obligations, expected	$ 24