Fair Value (Recurring Measurements) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Debt securities:
Unsecured debentures	$ 427	[1]	$ 435	[1]
Certificates of deposit	109	[1]	151	[1]
Government debt securities	26	[1]	25	[1]
Subtotal	562	[1]	611	[1]
Equity securities:
Mutual funds	45	[1]	44	[1]
Subtotal	45	[1]	44	[1]
Total available-for-sale	607	[1]	655	[1]
Equity securities:
Mutual funds	13		13
Total trading	13		13
DERIVATIVES:
Total derivatives	222		240
TOTAL ASSETS	842		908
DERIVATIVES:
Total derivatives	475		371
TOTAL LIABILITIES	475		371
Interest rate derivatives [Member]
DERIVATIVES:
Total derivatives	46		98
DERIVATIVES:
Total derivatives	376		322
Cross currency derivatives [Member]
DERIVATIVES:
Total derivatives	4		5
DERIVATIVES:
Total derivatives	11		11
Foreign currency derivatives [Member]
DERIVATIVES:
Total derivatives	123		113
DERIVATIVES:
Total derivatives	44		21
Commodity derivatives [Member]
DERIVATIVES:
Total derivatives	49		24
DERIVATIVES:
Total derivatives	44		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		13
Total trading	13		13
DERIVATIVES:
Total derivatives	0		0
TOTAL ASSETS	13		13
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	427	[1]	435	[1]
Certificates of deposit	109	[1]	151	[1]
Government debt securities	26	[1]	25	[1]
Subtotal	562	[1]	611	[1]
Equity securities:
Mutual funds	45	[1]	44	[1]
Subtotal	45	[1]	44	[1]
Total available-for-sale	607	[1]	655	[1]
Equity securities:
Mutual funds	0		0
Total trading	0		0
DERIVATIVES:
Total derivatives	114		136
TOTAL ASSETS	721		791
DERIVATIVES:
Total derivatives	381		263
TOTAL LIABILITIES	381		263
Level 2 [Member] | Interest rate derivatives [Member]
DERIVATIVES:
Total derivatives	46		98
DERIVATIVES:
Total derivatives	289		221
Level 2 [Member] | Cross currency derivatives [Member]
DERIVATIVES:
Total derivatives	4		5
DERIVATIVES:
Total derivatives	11		11
Level 2 [Member] | Foreign currency derivatives [Member]
DERIVATIVES:
Total derivatives	18		15
DERIVATIVES:
Total derivatives	40		16
Level 2 [Member] | Commodity derivatives [Member]
DERIVATIVES:
Total derivatives	46		18
DERIVATIVES:
Total derivatives	41		15
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	108		104
TOTAL ASSETS	108		104
DERIVATIVES:
Total derivatives	94		108
TOTAL LIABILITIES	94		108
Level 3 [Member] | Interest rate derivatives [Member]
DERIVATIVES:
Total derivatives	0		0
DERIVATIVES:
Total derivatives	87		101
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	105		98
DERIVATIVES:
Total derivatives	4		5
Level 3 [Member] | Commodity derivatives [Member]
DERIVATIVES:
Total derivatives	3		6
DERIVATIVES:
Total derivatives	$ 3		$ 2

[1] Amortized cost approximated fair value at March 31, 2014 and December 31, 2013.