Derivative Financial Instruments and Hedging Activities Counterparty Risk and Collateral (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Derivative [Line Items]
Fair Value of Assets	$ 1,500
Collateral related to derivative instruments	0	70
Automotive [Member]
Derivative [Line Items]
Fair Value of Assets	241	218
Derivative asset instruments, adjustment for non-performance risk	(1)	(3)
Derivative liability instruments, adjusted for non-performance risk	(1)	(10)
Financial Services [Member]
Derivative [Line Items]
Fair Value of Assets	1,300	1,375
Derivative asset instruments, adjustment for non-performance risk	(14)	(54)
Derivative liability instruments, adjusted for non-performance risk	$ (5)	$ (7)