Assets and Liabilities of Businesses Held For Sale and Discontinued Operations (Narrative, Financial Information and NBCU) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			0 Months Ended		0 Months Ended	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Mar. 19, 2013 NBCU LLC [Member]	Mar. 19, 2013 NBCU LLC [Member] Commercial Real Estate Portfolio Segment [Member]	Jul. 15, 2013 Portugal Consumer Auto Personal Loan [Member]	Sep. 30, 2013 Machining And Fabrication Business [Member]
Financial Information For Businesses Held For Sale [Line Items]
Proceeds from Sale of Real Estate Held-for-investment				$ 1,430
Summarized financial information for business held for sale
Assets Held-for-sale, at Carrying Value	48		50
Liabilities of Assets Held-for-sale	2		6
Equity Method Investment, Ownership Percentage				49.00%
Proceeds from Divestiture of Businesses, Net of Cash Divested	232	0		11,997		83	108
Guaranteed Debt Included In Sale Of Asset				4,000
Preferred Stock, Value, Issued	0		0	725
Consideration Received For Sale Of Business				16,722
Pre Tax Gain On Sale Of Business				1,096	921
Gain On Sale Of Business Net Of Tax				$ 825	$ 564