Fair Value Measurements (Details 1) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Fair value of assets and liabilities on recurring basis
Derivative financial assets	$ 183
Securities available-for-sale	151	188
Derivative related liabilities		26
Recurring [Member]
Fair value of assets and liabilities on recurring basis
Derivative financial assets	183
Securities available-for-sale	151	188
Total assets	334	188
Due to affiliate, carried at fair value	(466)	(447)
Long-term debt carried at fair value	(11,288)	(13,664)
Derivative related liabilities		(26)
Total liabilities	(11,754)	(14,137)
Interest rate swaps [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Derivative financial assets	617	973
Derivative related liabilities	(1,748)	(1,762)
Currency swaps [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Derivative financial assets	1,185	1,503
Derivative related liabilities	(221)	(163)
Foreign exchange forward [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Derivative related liabilities		(3)
Derivative netting [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Derivative financial assets	(1,619)	(2,476)
Derivative related liabilities	1,969	1,902
U.S. Treasury [Member]
Fair value of assets and liabilities on recurring basis
Securities available-for-sale		80
U.S. Treasury [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Available-for-sale securities		80
U.S. government sponsored enterprises [Member]
Fair value of assets and liabilities on recurring basis
Securities available-for-sale	1	1
U.S. government sponsored enterprises [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Available-for-sale securities	1	1
U.S. Corporate Debt Securities [Member]
Fair value of assets and liabilities on recurring basis
Securities available-for-sale	62	57
U.S. Corporate Debt Securities [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Available-for-sale securities	62	57
Government [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Available-for-sale securities	3
Corporate [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Available-for-sale securities	45	26
Equity securities [Member]
Fair value of assets and liabilities on recurring basis
Securities available-for-sale	10	10
Equity securities [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Available-for-sale securities	10	10
Money market funds [Member]
Fair value of assets and liabilities on recurring basis
Securities available-for-sale	29	13
Money market funds [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Available-for-sale securities	29	13
Accrued Interest [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Securities available-for-sale	1	1
Level 1 [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Securities available-for-sale	39	103
Total assets	39	103
Level 1 [Member] \| U.S. Treasury [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Available-for-sale securities		80
Level 1 [Member] \| Equity securities [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Available-for-sale securities	10	10
Level 1 [Member] \| Money market funds [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Available-for-sale securities	29	13
Level 2 [Member]
Fair value of assets and liabilities on recurring basis
Derivative financial assets	183
Due to affiliate, carried at fair value	466
Long-term debt carried at fair value	11,288
Level 2 [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Derivative financial assets	1,802	2,476
Securities available-for-sale	112	85
Total assets	1,914	2,561
Due to affiliate, carried at fair value	(466)	(447)
Long-term debt carried at fair value	(11,288)	(13,664)
Derivative related liabilities	(1,969)	(1,928)
Total liabilities	(13,723)	(16,039)
Level 2 [Member] \| Interest rate swaps [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Derivative financial assets	617	973
Derivative related liabilities	(1,748)	(1,762)
Level 2 [Member] \| Currency swaps [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Derivative financial assets	1,185	1,503
Derivative related liabilities	(221)	(163)
Level 2 [Member] \| Foreign exchange forward [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Derivative related liabilities		(3)
Level 2 [Member] \| U.S. government sponsored enterprises [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Available-for-sale securities	1	1
Level 2 [Member] \| U.S. Corporate Debt Securities [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Available-for-sale securities	62	57
Level 2 [Member] \| Government [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Available-for-sale securities	3
Level 2 [Member] \| Corporate [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Available-for-sale securities	45	26
Level 2 [Member] \| Accrued Interest [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Securities available-for-sale	1	1
Level 3 [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Available-for-sale securities
Total assets
Level 3 [Member] \| U.S. Corporate Debt Securities [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Available-for-sale securities
Level 3 [Member] \| Government [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Available-for-sale securities
Netting [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Derivative financial assets	(1,619)	(2,476)
Total assets	(1,619)	(2,476)
Derivative related liabilities	1,969	1,902
Total liabilities	1,969	1,902
Netting [Member] \| Derivative netting [Member] \| Recurring [Member]
Fair value of assets and liabilities on recurring basis
Derivative financial assets	(1,619)	(2,476)
Derivative related liabilities	$ 1,969	$ 1,902

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15D

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 12

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 16

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15C

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7534914&loc=d3e22054-111558

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

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-Paragraph 15E

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Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 13

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 14

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 10: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 22

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+ Details

- Definition

Fair values as of the balance sheet date of all assets resulting from contracts that meet the criteria of being accounted for as derivative instruments, net of the effects of master netting arrangements.

+ References+ Details

- Definition

Fair values as of the balance sheet date of all liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments, net of the effects of master netting arrangements.

+ References+ Details