Fair Value Measurements - Reconciliation of Changes in Level 3 Balances (Details) (Fair Value, Measurements, Recurring [Member], Level 3 [Member], USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Automotive [Member]
Reconciliation of Changes in Level 3 Balances [Abstract]
Beginning balance	$ (70)	$ 40
Realized/unrealized gains/(losses) [Abstract]
Cost of sales (assets and liabilities, net)	1	(86)
Interest income and other income/(loss), net (assets and liabilities, net)	(4)	(3)
Other comprehensive income/(loss) (assets and liabilities, net)
Total realized/unrealized gains/(losses) (assets and liabilities, net)	(3)	(89)
Purchases, issues, sales, settlements
Purchases (assets and liabilities, net)		7
Issues (assets and liabilities, net)
Sales (assets and liabilities, net)		(1)
Settlements (assets and liabilities, net)	52	(29)
Total purchases, issues, sales, settlements (assets and liabilities, net)	52	(23)
Transfers into Level 3
Transfers out of Level 3	(10)	(4)
Ending balance	(31)	(76)
Unrealized gains/(losses) on instruments still held	(2)	(79)
Automotive [Member] | Marketable securities [Member]
Reconciliation of Changes in Level 3 Balances [Abstract]
Fair Value Beginning Balance		2
Realized/unrealized gains/(losses) [Abstract]
Cost of sales (assets)
Interest income and other income/(loss), net (assets)		(1)
Other comprehensive income/(loss) (assets)
Total realized/unrealized gains/(losses) (assets)		(1)
Purchases, issues, sales, settlements
Purchases (assets)		7
Issues (assets)
Sales (assets)		(1)
Settlements (assets)
Total purchases, issues, sales, settlements (assets)		6
Transfers into Level 3
Transfers out of Level 3		(6)
Fair Value Ending Balance		1
Unrealized gains/(losses) on instruments still held
Automotive [Member] | Derivative financial instruments [Member]
Reconciliation of Changes in Level 3 Balances [Abstract]
Beginning balance	(70)	38
Realized/unrealized gains/(losses) [Abstract]
Cost of sales (assets and liabilities, net)	1	(86)
Interest income and other income/(loss), net (assets and liabilities, net)	(4)	(2)
Other comprehensive income/(loss) (assets and liabilities, net)		0
Total realized/unrealized gains/(losses) (assets and liabilities, net)	(3)	(88)
Purchases, issues, sales, settlements
Purchases (assets and liabilities, net)		0
Issues (assets and liabilities, net)		0
Sales (assets and liabilities, net)		0
Settlements (assets and liabilities, net)	52	(29)
Total purchases, issues, sales, settlements (assets and liabilities, net)	52	(29)
Transfers into Level 3		0
Transfers out of Level 3	(10)	2
Ending balance	(31)	(77)
Unrealized gains/(losses) on instruments still held	(2)	(79)
Financial Services [Member]
Reconciliation of Changes in Level 3 Balances [Abstract]
Beginning balance	137	(88)
Realized/unrealized gains/(losses) [Abstract]
Other income/(loss), net (assets and liabilities, net)	(81)	398
Other comprehensive income/(loss) (assets and liabilities, net)		(1)
Interest income/(expense) (assets and liabilities, net)		65
Total realized/unrealized gains/(losses) (assets and liabilities, net)	(81)	462
Purchases, issues, sales, settlements
Purchases (assets and liabilities, net)		5
Issues (assets and liabilities, net)		73
Sales (assets and liabilities, net)
Settlements (assets and liabilities, net)	(56)	108
Total purchases, issues, sales, settlements (assets and liabilities, net)	(56)	186
Transfers into Level 3
Transfers out of Level 3		(19)
Ending balance		541
Unrealized gains/(losses) on instruments still held		481
Financial Services [Member] | Marketable securities [Member]
Reconciliation of Changes in Level 3 Balances [Abstract]
Fair Value Beginning Balance		1
Realized/unrealized gains/(losses) [Abstract]
Other income/(loss), net (assets)
Other comprehensive income/(loss) (assets)
Interest income/(expense) (assets)
Total realized/unrealized gains/(losses) (assets)
Purchases, issues, sales, settlements
Purchases (assets)		5
Issues (assets)
Sales (assets)
Settlements (assets)
Total purchases, issues, sales, settlements (assets)		5
Transfers into Level 3
Transfers out of Level 3		(6)
Fair Value Ending Balance
Unrealized gains/(losses) on instruments still held
Financial Services [Member] | Derivative financial instruments [Member]
Reconciliation of Changes in Level 3 Balances [Abstract]
Beginning balance	137	(89)
Realized/unrealized gains/(losses) [Abstract]
Other income/(loss), net (assets and liabilities, net)	(81)	398
Other comprehensive income/(loss) (assets and liabilities, net)		(1)
Interest income/(expense) (assets and liabilities, net)		65
Total realized/unrealized gains/(losses) (assets and liabilities, net)	(81)	462
Purchases, issues, sales, settlements
Purchases (assets and liabilities, net)		0
Issues (assets and liabilities, net)		73
Sales (assets and liabilities, net)		0
Settlements (assets and liabilities, net)	(56)	108
Total purchases, issues, sales, settlements (assets and liabilities, net)	(56)	181
Transfers into Level 3		0
Transfers out of Level 3		(13)
Ending balance		541
Unrealized gains/(losses) on instruments still held		$ 481