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	12 Months Ended
	Dec. 31, 2012	Dec. 31, 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)	11	(99)
Interest income and other income/(loss), net (assets and liabilities, net)	(4)	(2)
Other comprehensive income/(loss) (assets and liabilities, net)
Total realized/unrealized gains/(losses) (assets and liabilities, net)	7	(101)
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)	65	(14)
Total purchases, issues, sales, settlements (assets and liabilities, net)	65	(8)
Transfers into Level 3
Transfers out of Level 3	(10)	(1)
Ending balance	(8)	(70)
Unrealized gains/(losses) on instruments still held	9	(69)
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		(7)
Fair Value Ending Balance
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)	11	(99)
Interest income and other income/(loss), net (assets and liabilities, net)	(4)	(1)
Other comprehensive income/(loss) (assets and liabilities, net)		0
Total realized/unrealized gains/(losses) (assets and liabilities, net)	7	(100)
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)	65	(14)
Total purchases, issues, sales, settlements (assets and liabilities, net)	65	(14)
Transfers into Level 3		0
Transfers out of Level 3	(10)	6
Ending balance	(8)	(70)
Unrealized gains/(losses) on instruments still held	9	(69)
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)	382
Other comprehensive income/(loss) (assets and liabilities, net)		(1)
Interest income/(expense) (assets and liabilities, net)		90
Total realized/unrealized gains/(losses) (assets and liabilities, net)	(81)	471
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)	114
Total purchases, issues, sales, settlements (assets and liabilities, net)	(56)	192
Transfers into Level 3
Transfers out of Level 3		(438)
Ending balance		137
Unrealized gains/(losses) on instruments still held		65
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)	382
Other comprehensive income/(loss) (assets and liabilities, net)		(1)
Interest income/(expense) (assets and liabilities, net)		90
Total realized/unrealized gains/(losses) (assets and liabilities, net)	(81)	471
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)	114
Total purchases, issues, sales, settlements (assets and liabilities, net)	(56)	187
Transfers into Level 3		0
Transfers out of Level 3		(432)
Ending balance		137
Unrealized gains/(losses) on instruments still held		$ 65