Fair Value (Recurring Measurements) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
Debt securities:
Unsecured debentures	$ 665	[1]	$ 448	[1]
Certificates of deposit	148	[1]	143	[1]
Government debt securities	26	[1]	34	[1]
Subtotal	839	[1]	625	[1]
Equity securities:
Mutual funds	46	[1]	56	[1]
Subtotal	46	[1]	56	[1]
Total available-for-sale	885	[1]	681	[1]
Equity securities:
Mutual funds	13		12
Total trading	13		12
DERIVATIVES:
Total derivatives	198		100
TOTAL ASSETS	1,096		793
DERIVATIVES:
Total derivatives	396		602
TOTAL LIABILITIES	396		602
Interest rate derivatives [Member]
DERIVATIVES:
Total derivatives	44		2
DERIVATIVES:
Total derivatives	352		565
Cross currency derivatives [Member]
DERIVATIVES:
Total derivatives	6		6
DERIVATIVES:
Total derivatives	3		6
Foreign currency derivatives [Member]
DERIVATIVES:
Total derivatives	114		81
DERIVATIVES:
Total derivatives	21		14
Commodity derivatives [Member]
DERIVATIVES:
Total derivatives	34		11
DERIVATIVES:
Total derivatives	20		17
Level 1 [Member]
Debt securities:
Unsecured debentures	0	[1]	0	[1]
Certificates of deposit	0	[1]	0	[1]
Government debt securities	0	[1]	0	[1]
Subtotal	0	[1]	0	[1]
Equity securities:
Mutual funds	0	[1]	0	[1]
Subtotal	0	[1]	0	[1]
Total available-for-sale	0	[1]	0	[1]
Equity securities:
Mutual funds	13		12
Total trading	13		12
DERIVATIVES:
Total derivatives	0		0
TOTAL ASSETS	13		12
DERIVATIVES:
Total derivatives	0		0
TOTAL LIABILITIES	0		0
Level 1 [Member] | Interest rate derivatives [Member]
DERIVATIVES:
Total derivatives	0		0
DERIVATIVES:
Total derivatives	0		0
Level 1 [Member] | Cross currency derivatives [Member]
DERIVATIVES:
Total derivatives	0		0
DERIVATIVES:
Total derivatives	0		0
Level 1 [Member] | Foreign currency derivatives [Member]
DERIVATIVES:
Total derivatives	0		0
DERIVATIVES:
Total derivatives	0		0
Level 1 [Member] | Commodity derivatives [Member]
DERIVATIVES:
Total derivatives	0		0
DERIVATIVES:
Total derivatives	0		0
Level 2 [Member]
Debt securities:
Unsecured debentures	665	[1]	448	[1]
Certificates of deposit	148	[1]	143	[1]
Government debt securities	26	[1]	34	[1]
Subtotal	839	[1]	625	[1]
Equity securities:
Mutual funds	46	[1]	56	[1]
Subtotal	46	[1]	56	[1]
Total available-for-sale	885	[1]	681	[1]
Equity securities:
Mutual funds	0		0
Total trading	0		0
DERIVATIVES:
Total derivatives	93		18
TOTAL ASSETS	978		699
DERIVATIVES:
Total derivatives	283		179
TOTAL LIABILITIES	283		179
Level 2 [Member] | Interest rate derivatives [Member]
DERIVATIVES:
Total derivatives	44		2
DERIVATIVES:
Total derivatives	249		153
Level 2 [Member] | Cross currency derivatives [Member]
DERIVATIVES:
Total derivatives	6		6
DERIVATIVES:
Total derivatives	3		6
Level 2 [Member] | Foreign currency derivatives [Member]
DERIVATIVES:
Total derivatives	17		2
DERIVATIVES:
Total derivatives	15		7
Level 2 [Member] | Commodity derivatives [Member]
DERIVATIVES:
Total derivatives	26		8
DERIVATIVES:
Total derivatives	16		13
Level 3 [Member]
Debt securities:
Unsecured debentures	0	[1]	0	[1]
Certificates of deposit	0	[1]	0	[1]
Government debt securities	0	[1]	0	[1]
Subtotal	0	[1]	0	[1]
Equity securities:
Mutual funds	0	[1]	0	[1]
Subtotal	0	[1]	0	[1]
Total available-for-sale	0	[1]	0	[1]
Equity securities:
Mutual funds	0		0
Total trading	0		0
DERIVATIVES:
Total derivatives	105		82
TOTAL ASSETS	105		82
DERIVATIVES:
Total derivatives	113		423
TOTAL LIABILITIES	113		423
Level 3 [Member] | Interest rate derivatives [Member]
DERIVATIVES:
Total derivatives	0		0
DERIVATIVES:
Total derivatives	103		412
Level 3 [Member] | Cross currency derivatives [Member]
DERIVATIVES:
Total derivatives	0		0
DERIVATIVES:
Total derivatives	0		0
Level 3 [Member] | Foreign currency derivatives [Member]
DERIVATIVES:
Total derivatives	97		79
DERIVATIVES:
Total derivatives	6		7
Level 3 [Member] | Commodity derivatives [Member]
DERIVATIVES:
Total derivatives	8		3
DERIVATIVES:
Total derivatives	$ 4		$ 4

[1] Amortized cost approximated fair value at September 30, 2013 and December 31, 2012.