Assets And Liabilities Measured At Fair Value On A Recurring Basis (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010
Assets
Auction rate securities	$ 118
Fair Value, Measurements, Recurring
Assets
Derivative contracts	337		342
Auction rate securities	118		153
Total	40,369		30,818
Liabilities
Derivative contracts	6		8
Total	6		8
Fair Value, Measurements, Recurring | Time deposits
Assets
Cash equivalents	534		973
Marketable securities	495		307
Fair Value, Measurements, Recurring | Money market and other funds
Assets
Cash equivalents	4,462		7,547
Fair Value, Measurements, Recurring | U.S. government notes
Assets
Cash equivalents			300
Marketable securities	11,579		3,930
Fair Value, Measurements, Recurring | Foreign government bonds
Assets
Cash equivalents			150
Marketable securities	1,629		1,172
Fair Value, Measurements, Recurring | Corporate debt securities
Assets
Cash equivalents			8
Marketable securities	6,112		5,742
Fair Value, Measurements, Recurring | U.S. government agencies
Assets
Cash equivalents	275
Marketable securities	6,226		1,857
Fair Value, Measurements, Recurring | Municipal securities
Assets
Marketable securities	1,794		2,503
Fair Value, Measurements, Recurring | Agency residential mortgage-backed securities
Assets
Marketable securities	6,501		5,673
Fair Value, Measurements, Recurring | Marketable equity securities
Assets
Marketable securities	307		161
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Derivative contracts	0		0
Auction rate securities	0		0
Total	15,088		10,327
Liabilities
Derivative contracts	0		0
Total	0		0
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Quoted Prices in Active Markets for Identical Assets (Level 1) | Time deposits
Assets
Cash equivalents	0		0
Marketable securities	0		0
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Quoted Prices in Active Markets for Identical Assets (Level 1) | Money market and other funds
Assets
Cash equivalents	3,202		5,936
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. government notes
Assets
Cash equivalents			300
Marketable securities	11,579		3,930
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Quoted Prices in Active Markets for Identical Assets (Level 1) | Foreign government bonds
Assets
Cash equivalents			0
Marketable securities	0		0
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate debt securities
Assets
Cash equivalents			0
Marketable securities	0		0
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. government agencies
Assets
Cash equivalents	0
Marketable securities	0		0
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Quoted Prices in Active Markets for Identical Assets (Level 1) | Municipal securities
Assets
Marketable securities	0		0
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Quoted Prices in Active Markets for Identical Assets (Level 1) | Agency residential mortgage-backed securities
Assets
Marketable securities	0		0
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Quoted Prices in Active Markets for Identical Assets (Level 1) | Marketable equity securities
Assets
Marketable securities	307		161
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Significant Other Observable Inputs (Level 2)
Assets
Derivative contracts	337		342
Auction rate securities	0		0
Total	25,163		20,338
Liabilities
Derivative contracts	6		8
Total	6		8
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Significant Other Observable Inputs (Level 2) | Time deposits
Assets
Cash equivalents	534		973
Marketable securities	495		307
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Significant Other Observable Inputs (Level 2) | Money market and other funds
Assets
Cash equivalents	1,260	[1]	1,611	[1]
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Significant Other Observable Inputs (Level 2) | U.S. government notes
Assets
Cash equivalents			0
Marketable securities	0		0
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Significant Other Observable Inputs (Level 2) | Foreign government bonds
Assets
Cash equivalents			150
Marketable securities	1,629		1,172
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Significant Other Observable Inputs (Level 2) | Corporate debt securities
Assets
Cash equivalents			8
Marketable securities	6,112		5,742
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Significant Other Observable Inputs (Level 2) | U.S. government agencies
Assets
Cash equivalents	275
Marketable securities	6,226		1,857
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Significant Other Observable Inputs (Level 2) | Municipal securities
Assets
Marketable securities	1,794		2,503
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Significant Other Observable Inputs (Level 2) | Agency residential mortgage-backed securities
Assets
Marketable securities	6,501		5,673
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Significant Other Observable Inputs (Level 2) | Marketable equity securities
Assets
Marketable securities	0		0
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Significant Unobservable Inputs (Level 3)
Assets
Derivative contracts	0		0
Auction rate securities	118		153
Total	118		153
Liabilities
Derivative contracts	0		0
Total	0		0
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Significant Unobservable Inputs (Level 3) | Time deposits
Assets
Cash equivalents	0		0
Marketable securities	0		0
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Significant Unobservable Inputs (Level 3) | Money market and other funds
Assets
Cash equivalents	0		0
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Significant Unobservable Inputs (Level 3) | U.S. government notes
Assets
Cash equivalents			0
Marketable securities	0		0
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Significant Unobservable Inputs (Level 3) | Foreign government bonds
Assets
Cash equivalents			0
Marketable securities	0		0
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Significant Unobservable Inputs (Level 3) | Corporate debt securities
Assets
Cash equivalents			0
Marketable securities	0		0
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Significant Unobservable Inputs (Level 3) | U.S. government agencies
Assets
Cash equivalents	0
Marketable securities	0		0
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Significant Unobservable Inputs (Level 3) | Municipal securities
Assets
Marketable securities	0		0
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Significant Unobservable Inputs (Level 3) | Agency residential mortgage-backed securities
Assets
Marketable securities	0		0
Fair Value, Measurements, Recurring | Fair value measurement at reporting date using Significant Unobservable Inputs (Level 3) | Marketable equity securities
Assets
Marketable securities	$ 0		$ 0

[1] This balance represents cash collateral received in connection with our securities lending program, which was invested in reverse repurchase agreements maturing within three months.