Assets and Liabilities of Businesses Held For Sale and Discontinued Operations (Held for Sale Narrative) (Details) (USD $) In Millions, unless otherwise specified	0 Months Ended	3 Months Ended			0 Months Ended		0 Months Ended				3 Months Ended
	Jan. 28, 2011	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011	Jan. 28, 2011 NBC Universal [Member]	Mar. 31, 2011 NBC Universal [Member]	Jan. 28, 2011 NBCU LLC [Member]	Mar. 31, 2012 NBCU LLC [Member]	Dec. 31, 2011 NBCU LLC [Member]	Mar. 31, 2011 NBCU LLC [Member]	Mar. 31, 2011 Consumer RV Marine [Member]	Jun. 30, 2011 Consumer Mexico [Member]	Jan. 28, 2011 Comcast [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash proceeds from sale of NBCU		$ 0	$ 1,775		$ 6,176
Ownership Percentage In Newly Formed Entity					49.00%								51.00%
Transaction Related Cost Reimbursements Related To Sale Of Business					49
Redemption Rights That Would Cause Sale Of Half Ownership							three and a half years
Redemption Rights That Would Cause Sale Of Remaining Half Ownership	seven years
Pre Tax Gain On Sale Of Business						3,557
Gain On Sale Of Business Net Of Tax						400
Tax Effect On Gain On Sale Of Business										3,157
Deferred Tax Liabilities								4,912	4,880
Equity Method Investment, Ownership Percentage		1.00%
Equity Method Investments								18,134	17,955
Deferred income taxes		281		(131)
Assets of businesses held for sale		640		711
Liabilities of businesses held for sale		305		345
Current receivables		19,040		19,531
Property, plant and equipment - net		66,000		65,739
Other assets, all		108,563		111,701
Accounts Payable, Current		17,031		16,400
Accrued Liabilities, Current		15,030		14,796
Other Liabilities		67,191		70,653
Consideration Received For Sale Of Business											$ 2,365	$ 1,943