Fair Value (Recurring Measurements) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Debt securities:
Unsecured debentures	$ 415	[1]	$ 448	[1]
Certificates of deposit	196	[1]	143	[1]
Government debt securities	25	[1]	34	[1]
Subtotal	636	[1]	625	[1]
Equity securities:
Mutual funds	52	[1]	56	[1]
Subtotal	52	[1]	56	[1]
Total available-for-sale	688	[1]	681	[1]
Equity securities:
Mutual funds	13		12
Total trading	13		12
DERIVATIVES:
Total derivatives	188		100
TOTAL ASSETS	889		793
DERIVATIVES:
Total derivatives	506		657
TOTAL LIABILITIES	506		657
Interest rate derivatives [Member]
DERIVATIVES:
Total derivatives	40		2
DERIVATIVES:
Total derivatives	389		565
Cross currency derivatives [Member]
DERIVATIVES:
Total derivatives	5		6
DERIVATIVES:
Total derivatives	8		6
Foreign currency derivatives [Member]
DERIVATIVES:
Total derivatives	104		81
DERIVATIVES:
Total derivatives	24		14
Commodity derivatives [Member]
DERIVATIVES:
Total derivatives	39		11
DERIVATIVES:
Total derivatives	85		72
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	415	[1]	448	[1]
Certificates of deposit	196	[1]	143	[1]
Government debt securities	25	[1]	34	[1]
Subtotal	636	[1]	625	[1]
Equity securities:
Mutual funds	52	[1]	56	[1]
Subtotal	52	[1]	56	[1]
Total available-for-sale	688	[1]	681	[1]
Equity securities:
Mutual funds	0		0
Total trading	0		0
DERIVATIVES:
Total derivatives	98		18
TOTAL ASSETS	786		699
DERIVATIVES:
Total derivatives	367		179
TOTAL LIABILITIES	367		179
Level 2 [Member] | Interest rate derivatives [Member]
DERIVATIVES:
Total derivatives	40		2
DERIVATIVES:
Total derivatives	326		153
Level 2 [Member] | Cross currency derivatives [Member]
DERIVATIVES:
Total derivatives	5		6
DERIVATIVES:
Total derivatives	8		6
Level 2 [Member] | Foreign currency derivatives [Member]
DERIVATIVES:
Total derivatives	26		2
DERIVATIVES:
Total derivatives	16		7
Level 2 [Member] | Commodity derivatives [Member]
DERIVATIVES:
Total derivatives	27		8
DERIVATIVES:
Total derivatives	17		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	90		82
TOTAL ASSETS	90		82
DERIVATIVES:
Total derivatives	139		478
TOTAL LIABILITIES	139		478
Level 3 [Member] | Interest rate derivatives [Member]
DERIVATIVES:
Total derivatives	0		0
DERIVATIVES:
Total derivatives	63		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	78		79
DERIVATIVES:
Total derivatives	8		7
Level 3 [Member] | Commodity derivatives [Member]
DERIVATIVES:
Total derivatives	12		3
DERIVATIVES:
Total derivatives	$ 68		$ 59

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