Fair Value (Recurring Measurements) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014
Debt securities:
Unsecured debentures	$ 410	[1]	$ 501	[1]
Certificates of deposit	139	[1]	151	[1]
Government debt securities	35	[1]	57	[1]
Subtotal	584	[1]	709	[1]
Equity securities:
Mutual funds	24	[1]	25	[1]
Subtotal	24	[1]	25	[1]
Total available for sale	608	[1]	734	[1]
Equity securities:
Mutual funds	15		15
Total trading	15		15
DERIVATIVES:
Total derivatives	307		280
TOTAL ASSETS	930		1,029
DERIVATIVES:
Total derivatives	596		514
TOTAL LIABILITIES	596		514
Interest rate derivatives [Member]
DERIVATIVES:
Total derivatives	469		416
Cross currency derivatives [Member]
DERIVATIVES:
Total derivatives	33		29
Foreign currency derivatives [Member]
DERIVATIVES:
Total derivatives	261		236
DERIVATIVES:
Total derivatives	66		52
Commodity Contract [Member]
DERIVATIVES:
Total derivatives	46		44
DERIVATIVES:
Total derivatives	28		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	15		15
Total trading	15		15
DERIVATIVES:
Total derivatives	0		0
TOTAL ASSETS	15		15
DERIVATIVES:
Total derivatives	0		0
TOTAL LIABILITIES	0		0
Level 1 [Member] | Interest rate derivatives [Member]
DERIVATIVES:
Total derivatives	0		0
Level 1 [Member] | Cross currency derivatives [Member]
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 Contract [Member]
DERIVATIVES:
Total derivatives	0		0
DERIVATIVES:
Total derivatives	0		0
Level 2 [Member]
Debt securities:
Unsecured debentures	410	[1]	501	[1]
Certificates of deposit	139	[1]	151	[1]
Government debt securities	35	[1]	57	[1]
Subtotal	584	[1]	709	[1]
Equity securities:
Mutual funds	24	[1]	25	[1]
Subtotal	24	[1]	25	[1]
Total available for sale	608	[1]	734	[1]
Equity securities:
Mutual funds	0		0
Total trading	0		0
DERIVATIVES:
Total derivatives	63		55
TOTAL ASSETS	671		789
DERIVATIVES:
Total derivatives	244		294
TOTAL LIABILITIES	244		294
Level 2 [Member] | Interest rate derivatives [Member]
DERIVATIVES:
Total derivatives	167		206
Level 2 [Member] | Cross currency derivatives [Member]
DERIVATIVES:
Total derivatives	0		29
Level 2 [Member] | Foreign currency derivatives [Member]
DERIVATIVES:
Total derivatives	21		18
DERIVATIVES:
Total derivatives	49		43
Level 2 [Member] | Commodity Contract [Member]
DERIVATIVES:
Total derivatives	42		37
DERIVATIVES:
Total derivatives	28		16
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	244		225
TOTAL ASSETS	244		225
DERIVATIVES:
Total derivatives	352		220
TOTAL LIABILITIES	352		220
Level 3 [Member] | Interest rate derivatives [Member]
DERIVATIVES:
Total derivatives	302		210
Level 3 [Member] | Cross currency derivatives [Member]
DERIVATIVES:
Total derivatives	33		0
Level 3 [Member] | Foreign currency derivatives [Member]
DERIVATIVES:
Total derivatives	240		218
DERIVATIVES:
Total derivatives	17		9
Level 3 [Member] | Commodity Contract [Member]
DERIVATIVES:
Total derivatives	4		7
DERIVATIVES:
Total derivatives	$ 0		$ 1

[1] Amortized cost approximated fair value at March 31, 2015 and December 31, 2014.