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	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Marketable securities [Member]
Reconciliation of Changes in Level 3 Balances [Abstract]
Net Transfers Into/(Out of) Level 3		$ (2)
Derivative financial instruments [Member]
Reconciliation of Changes in Level 3 Balances [Abstract]
Net Transfers Into/(Out of) Level 3	(10)	(1)
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)	23	(10)
Interest income and other non-operating income/(expense), net (assets and liabilities, net)	(4)	(1)
Other comprehensive income/(loss) (assets and liabilities, net)
Total realized/unrealized gains/(losses) (assets and liabilities, net)	19	(11)
Purchases, issues, sales, settlements
Purchases (assets and liabilities, net)		2
Issues (assets and liabilities, net)
Sales (assets and liabilities, net)		(1)
Settlements (assets and liabilities, net)	17	(26)
Total purchases, issues, sales, settlements (assets and liabilities, net)	17	(25)
Transfers into Level 3 (assets and liabilities, net)
Transfers out of Level 3 (assets and liabilities, net)	(10)	(1)
Ending balance	(44)	3
Unrealized gains/(losses) on instruments still held	13	(11)
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 non-operating income/(expense), net (assets)		(1)
Other comprehensive income/(loss) (assets)
Total realized/unrealized gains/(losses) (assets)		(1)
Purchases, issues, sales, settlements
Purchases (assets)		2
Issues (assets)
Sales (assets)		(1)
Settlements (assets)
Total purchases, issues, sales, settlements (assets)		1
Transfers into Level 3 (assets and liabilities, net)
Transfers out of Level 3 (assets and liabilities, net)		(1)
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)	23	(10)
Interest income and other non-operating income/(expense), net (assets and liabilities, net)	(4)
Other comprehensive income/(loss) (assets and liabilities, net)
Total realized/unrealized gains/(losses) (assets and liabilities, net)	19	(10)
Purchases, issues, sales, settlements
Purchases (assets and liabilities, net)
Issues (assets and liabilities, net)
Sales (assets and liabilities, net)
Settlements (assets and liabilities, net)	17	(26)
Total purchases, issues, sales, settlements (assets and liabilities, net)	17	(26)
Transfers into Level 3 (assets and liabilities, net)
Transfers out of Level 3 (assets and liabilities, net)	(10)
Ending balance	(44)	2
Unrealized gains/(losses) on instruments still held	13	(11)
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)	(38)	(23)
Other comprehensive income/(loss) (assets and liabilities, net)		(1)
Interest income/(expense) (assets and liabilities, net)		5
Total realized/unrealized gains/(losses) (assets and liabilities, net)	(38)	(19)
Purchases, issues, sales, settlements
Purchases (assets and liabilities, net)
Issues (assets and liabilities, net)
Sales (assets and liabilities, net)
Settlements (assets and liabilities, net)		48
Total purchases, issues, sales, settlements (assets and liabilities, net)		48
Transfers into Level 3 (assets and liabilities, net)
Transfers out of Level 3 (assets and liabilities, net)		(2)
Ending balance	99	(61)
Unrealized gains/(losses) on instruments still held	(38)	22
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)
Issues (assets)
Sales (assets)
Settlements (assets)
Total purchases, issues, sales, settlements (assets)
Transfers into Level 3 (assets and liabilities, net)
Transfers out of Level 3 (assets and liabilities, net)		(1)
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)	(38)	(23)
Other comprehensive income/(loss) (assets and liabilities, net)		(1)
Interest income/(expense) (assets and liabilities, net)		5
Total realized/unrealized gains/(losses) (assets and liabilities, net)	(38)	(19)
Purchases, issues, sales, settlements
Purchases (assets and liabilities, net)
Issues (assets and liabilities, net)
Sales (assets and liabilities, net)
Settlements (assets and liabilities, net)		48
Total purchases, issues, sales, settlements (assets and liabilities, net)		48
Transfers into Level 3 (assets and liabilities, net)
Transfers out of Level 3 (assets and liabilities, net)		(1)
Ending balance	99	(61)
Unrealized gains/(losses) on instruments still held	$ (38)	$ 22