Benefit Obligations (Schedule of Fair Values of Pension Plan Assets) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets, fair value non-financial receivables	$ 26		$ 29
Pension plan assets, fair value non-financial payables	31		63
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	2,714	[1]	2,930	[1]
Total liabilities [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	55		20
Swaps [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	48		10
Other [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	1		0
Obligations Under Securities Lending [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	6		10
Total assets [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	2,769		2,950
Cash and Cash quivalents [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	8		15
Loans [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	51		55
Equities [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	179		176
Swaps [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	49		10
Other [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	0		1
US Companies [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	462		359
International Companies [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	426		450
Collateralized Mortgage Obligations [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	1		2
Corporate Debt [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	855		822
Treasuries, Other Debt [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	394		451
Mortgage Backed Securities [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	26		31
Registered Investment Companies [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	124		278
Securities Lending Collateral [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	6		10
Short-term Investments [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	131		229
Insurance Contracts [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	34		31
Other [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	23		30
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	915		948
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Total liabilities [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	6		10
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Swaps [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	0		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Other [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	0		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Obligations Under Securities Lending [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	6		10
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Total assets [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	921		958
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Cash and Cash quivalents [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	8		15
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Loans [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	0		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equities [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	0		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Swaps [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	0		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Other [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	0		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | US Companies [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	462		359
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | International Companies [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	426		450
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Collateralized Mortgage Obligations [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	0		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Corporate Debt [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	0		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Treasuries, Other Debt [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	4		102
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Mortgage Backed Securities [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	0		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Registered Investment Companies [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	0		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Securities Lending Collateral [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	6		10
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Short-term Investments [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	0		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Insurance Contracts [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	0		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Other [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	15		22
Significant Other Observable Inputs (Level 2) [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	1,799		1,982
Significant Other Observable Inputs (Level 2) [Member] | Total liabilities [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	49		10
Significant Other Observable Inputs (Level 2) [Member] | Swaps [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	48		10
Significant Other Observable Inputs (Level 2) [Member] | Other [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	1		0
Significant Other Observable Inputs (Level 2) [Member] | Obligations Under Securities Lending [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	0		0
Significant Other Observable Inputs (Level 2) [Member] | Total assets [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	1,848		1,992
Significant Other Observable Inputs (Level 2) [Member] | Cash and Cash quivalents [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	0		0
Significant Other Observable Inputs (Level 2) [Member] | Loans [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	51		55
Significant Other Observable Inputs (Level 2) [Member] | Equities [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	179		176
Significant Other Observable Inputs (Level 2) [Member] | Swaps [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	49		10
Significant Other Observable Inputs (Level 2) [Member] | Other [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	0		1
Significant Other Observable Inputs (Level 2) [Member] | US Companies [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	0		0
Significant Other Observable Inputs (Level 2) [Member] | International Companies [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	0		0
Significant Other Observable Inputs (Level 2) [Member] | Collateralized Mortgage Obligations [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	1		2
Significant Other Observable Inputs (Level 2) [Member] | Corporate Debt [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	855		822
Significant Other Observable Inputs (Level 2) [Member] | Treasuries, Other Debt [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	390		349
Significant Other Observable Inputs (Level 2) [Member] | Mortgage Backed Securities [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	26		31
Significant Other Observable Inputs (Level 2) [Member] | Registered Investment Companies [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	124		278
Significant Other Observable Inputs (Level 2) [Member] | Securities Lending Collateral [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	0		0
Significant Other Observable Inputs (Level 2) [Member] | Short-term Investments [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	131		229
Significant Other Observable Inputs (Level 2) [Member] | Insurance Contracts [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	34		31
Significant Other Observable Inputs (Level 2) [Member] | Other [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total net assets	$ 8		$ 8

[1] Total net assets excludes non-financial plan receivables and payables of $26 million and $31 million, respectively, as of December 31, 2013 and $29 million and $63 million, respectively, as of December 31, 2012. Non-financial items include due to/from broker, interest receivables and accrued expenses.