Cash, Cash Equivalents and Marketable Securities (Details) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2010	Dec. 31, 2009
Cash, cash equivalents and short- and long- term marketable securities
Cash and cash equivalents	$ 1,797	$ 1,622	$ 1,404	$ 1,397
Short-term marketable securities	829	1,035
Long-term marketable securities	1,174	1,401
Total	3,800	4,058
Cash [Member]
Cash, cash equivalents and short- and long- term marketable securities
Cash and cash equivalents	104	103
Short-term marketable securities	0	0
Long-term marketable securities	0	0
Total	104	103
Bank Deposits [Member]
Cash, cash equivalents and short- and long- term marketable securities
Cash and cash equivalents	812	455
Short-term marketable securities	0	0
Long-term marketable securities	0	0
Total	812	455
Certificates of Deposits [Member]
Cash, cash equivalents and short- and long- term marketable securities
Cash and cash equivalents	3
Short-term marketable securities	5
Long-term marketable securities	1
Total	9
Money market funds [Member]
Cash, cash equivalents and short- and long- term marketable securities
Cash and cash equivalents	212	641
Short-term marketable securities	0	0
Long-term marketable securities	0	0
Total	212	641
U.S. treasury and agency obligations [Member]
Cash, cash equivalents and short- and long- term marketable securities
Cash and cash equivalents	0	4
Short-term marketable securities	256	586
Long-term marketable securities	960	1,360
Total	1,216	1,950
Foreign government and agency obligations [Member]
Cash, cash equivalents and short- and long- term marketable securities
Cash and cash equivalents	0
Short-term marketable securities	1
Long-term marketable securities	5
Total	6
Commercial Paper [Member]
Cash, cash equivalents and short- and long- term marketable securities
Cash and cash equivalents	646	419
Short-term marketable securities	361	363
Long-term marketable securities	0	0
Total	1,007	782
Corporate bonds [Member]
Cash, cash equivalents and short- and long- term marketable securities
Cash and cash equivalents	20	0
Short-term marketable securities	199	86
Long-term marketable securities	198	41
Total	417	127
Asset-backed Securities and other [Member]
Cash, cash equivalents and short- and long- term marketable securities
Cash and cash equivalents	0
Short-term marketable securities	7
Long-term marketable securities	10
Total	$ 17