Fair Value Measurements (Non-Recurring Fair Value Measurements) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value assets measured on non recurring basis	$ 1,426	$ 2,412
Adjustments To Assets Measured At Fair Value On Non Recurring Basis	(1,953)	(1,371)
Impairment of Long-Lived Assets Held-for-use	732	242
Financing receivables and loans held for sale [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Adjustments To Assets Measured At Fair Value On Non Recurring Basis	(361)	(595)
Cost and equity method investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Adjustments To Assets Measured At Fair Value On Non Recurring Basis	(466)	(153)
Long Lived Assets, Including Real Estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Adjustments To Assets Measured At Fair Value On Non Recurring Basis	(1,126)	(623)
Private Equity And Real Estate Funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value assets measured on non recurring basis	93	84
Adjustments To Assets Measured At Fair Value On Non Recurring Basis	(10)	(33)
Impairment of Long-Lived Assets Held-for-use	108	218
Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value assets measured on non recurring basis	2,260	1,076
Fair Value, Inputs, Level 2 [Member] | Financing receivables and loans held for sale [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value assets measured on non recurring basis	210	366
Fair Value, Inputs, Level 2 [Member] | Cost and equity method investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value assets measured on non recurring basis	0	8
Fair Value, Inputs, Level 2 [Member] | Long Lived Assets, Including Real Estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value assets measured on non recurring basis	2,050	702
Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value assets measured on non recurring basis	4,720	6,589
Fair Value, Inputs, Level 3 [Member] | Financing receivables and loans held for sale [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value assets measured on non recurring basis	2,986	4,094
Fair Value, Inputs, Level 3 [Member] | Cost and equity method investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value assets measured on non recurring basis	649	313
Fair Value, Inputs, Level 3 [Member] | Long Lived Assets, Including Real Estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value assets measured on non recurring basis	$ 1,085	$ 2,182