Fair Value of Financial Assets and Liabilities - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended		12 Months Ended												12 Months Ended		12 Months Ended			12 Months Ended
	Dec. 31, 2013 Security	Dec. 31, 2012	Dec. 31, 2013 Minimum	Dec. 31, 2013 Maximum	Dec. 31, 2013 Municipal obligations	Dec. 31, 2012 Municipal obligations	Dec. 31, 2013 Publicly traded equity securities	Dec. 31, 2012 Publicly traded equity securities	Dec. 31, 2013 High yield corporate debt securities	Dec. 31, 2012 High yield corporate debt securities	Dec. 31, 2013 Asset-backed securities	Dec. 31, 2012 Asset-backed securities	Dec. 31, 2013 Securities (Assets)	Dec. 31, 2012 Securities (Assets)	Dec. 31, 2013 Foreign debt securities	Dec. 31, 2012 Foreign debt securities	Dec. 31, 2013 Foreign Sovereign Debt Securities	Dec. 31, 2013 Auction rate securities	Dec. 31, 2012 Auction rate securities	Dec. 31, 2013 Variable Rate Demand Note	Dec. 31, 2011 Terremark Worldwide, Inc. VMware	Dec. 31, 2012 XtremIO	Dec. 31, 2012 LenovoEMC	Dec. 31, 2013 LenovoEMC
Schedule of Available-for-sale Securities [Line Items]
Joint Venture, Ownership Interest Percentage																								49.00%
Number of Auction Rate Securities With Underlying Loans Which Have No Guarantees	1
Gain on sale of investment																					$ 56	$ 32
Available-for-sale securities					863	1,035	95	87	531	519	0	2	9,697	6,682	2,155	1,279		60	70
Average credit rating															A+		AAA	AA
Percentage of securities deemed soverign debt																	4.00%
Auction rate securities that have partial guarantees by the U.S. government, market value	7
Percentage of loans which collateralize auction rate securities guaranteed by FFELP	95.00%
Coupon rate used to estimate fair value of invesments - low end of range			0.00%
Coupon rate used to estimate fair value of invesments - high end of range				4.00%
Discount rate used to estimate fair value of investments	1.00%																						6.00%
Investment holding period	5 years
The rate used for the discount margin to determine the estimated fair value of investment in auction rate securities	1.00%
Short term investment, not classified in investments due within one year	$ 2,773	$ 1,422																		$ 76
Contractual maturity date																				Dec. 31, 2014