Fair Value Measurements (Non-Recurring) (Details) (USD $) In Millions, unless otherwise specified		3 Months Ended			9 Months Ended	3 Months Ended			9 Months Ended	3 Months Ended			9 Months Ended	3 Months Ended			9 Months Ended
	Sep. 30, 2012	Sep. 30, 2012 Financing receivables and loans held for sale [Member]	Jun. 30, 2012 Financing receivables and loans held for sale [Member]	Sep. 30, 2011 Financing receivables and loans held for sale [Member]	Sep. 30, 2011 Financing receivables and loans held for sale [Member]	Sep. 30, 2012 Cost and equity method investments [Member]	Jun. 30, 2012 Cost and equity method investments [Member]	Sep. 30, 2011 Cost and equity method investments [Member]	Sep. 30, 2011 Cost and equity method investments [Member]	Sep. 30, 2012 Long Lived Assets, Including Real Estate [Member]	Jun. 30, 2012 Long Lived Assets, Including Real Estate [Member]	Sep. 30, 2011 Long Lived Assets, Including Real Estate [Member]	Sep. 30, 2011 Long Lived Assets, Including Real Estate [Member]	Sep. 30, 2012 Total [Member]	Jun. 30, 2012 Total [Member]	Sep. 30, 2011 Total [Member]	Sep. 30, 2011 Total [Member]	Sep. 30, 2012 Fair Value, Inputs, Level 2 [Member] Financing receivables and loans held for sale [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 2 [Member] Financing receivables and loans held for sale [Member]	Sep. 30, 2012 Fair Value, Inputs, Level 2 [Member] Cost and equity method investments [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 2 [Member] Cost and equity method investments [Member]	Sep. 30, 2012 Fair Value, Inputs, Level 2 [Member] Long Lived Assets, Including Real Estate [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 2 [Member] Long Lived Assets, Including Real Estate [Member]	Sep. 30, 2012 Fair Value, Inputs, Level 2 [Member] Total [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 2 [Member] Total [Member]	Sep. 30, 2012 Fair Value, Inputs, Level 3 [Member] Financing receivables and loans held for sale [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 3 [Member] Financing receivables and loans held for sale [Member]	Sep. 30, 2012 Fair Value, Inputs, Level 3 [Member] Cost and equity method investments [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 3 [Member] Cost and equity method investments [Member]	Sep. 30, 2012 Fair Value, Inputs, Level 3 [Member] Long Lived Assets, Including Real Estate [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 3 [Member] Long Lived Assets, Including Real Estate [Member]	Sep. 30, 2012 Fair Value, Inputs, Level 3 [Member] Total [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 3 [Member] Total [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value assets measured on non recurring basis	$ 1,862																	$ 482	$ 158	$ 4	$ 0	$ 483	$ 1,343	$ 969	$ 1,501	$ 3,798	$ 5,159	$ 336	$ 402	$ 1,484	$ 3,254	$ 5,618	$ 8,815
Adjustments To Assets Measured At Fair Value On Non Recurring Basis		$ (411)	$ (225)	$ (254)	$ (716)	$ (105)	$ (50)	$ (84)	$ (254)	$ (473)	$ (271)	$ (367)	$ (1,262)	$ (989)	$ (546)	$ (705)	$ (2,232)