Fair Value Measurements Fair Value, Assets Measured on Nonrecurring Basis Using Unobservable Inputs (Details) (Fair Value Measurements Nonrecurring [Member], Level 3 [Member], USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Fair Value Measurements Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Operating lease equipment, Fair Value Disclosure	$ 28	$ 25
Operating lease equipment, Total Losses	(21)	(31)
Property, Plant, and Equipment, Fair Value Disclosure	6	18
Property Plant and Equipment, Total Losses	(5)	(5)
Total Fair Value	34	43
Total Losses	$ (26)	$ (36)