Customer Financing (Components Of Investment In Sales-Type Or Finance Leases) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Customer Financing [Abstract]
Minimum lease payments receivable	$ 1,987	$ 2,272
Estimated residual value of leased assets	544	541
Unearned income	(681)	(776)
Total	$ 1,850	$ 2,037