v3.2.0.727
Marketable Securities (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2015
Jun. 30, 2014
Jun. 30, 2015
Jun. 30, 2014
Dec. 31, 2014
Marketable Securities [Line Items]          
Total Marketable Securities $ 7,200   $ 7,200   $ 9,222
Total Cash and Cash Equivalents 17,627   17,627   18,954
Total Restricted Cash and Marketable Securities 2,065   2,065   2,273
Available-for-sale Securities, Due in one year or less 12,947   12,947    
Available-for-sale Securities, Due between one year and five years 2,024   2,024    
Total available-for-sale securities with contractual maturities 14,971   14,971    
Sales proceeds from investments classified as available-for-sale and sold prior to maturity 4,500 $ 748 5,900 $ 1,500  
Cash And Cash Equivalents [Member]          
Marketable Securities [Line Items]          
Available-for-sale Securities 10,388   10,388   10,890
Trading Securities 97   97   431
Total Marketable Securities 10,485   10,485   11,321
Cash, Cash Equivalents And Time Deposits 7,142   7,142   7,633
Cash And Cash Equivalents [Member] | Level 1 [Member] | Money Market Funds [Member]          
Marketable Securities [Line Items]          
Available-for-sale Securities 1,540   1,540   2,480
Cash And Cash Equivalents [Member] | Level 2 [Member] | U.S. government and agencies [Member]          
Marketable Securities [Line Items]          
Available-for-sale Securities 348   348   1,600
Cash And Cash Equivalents [Member] | Level 2 [Member] | Sovereign Debt [Member]          
Marketable Securities [Line Items]          
Available-for-sale Securities 3,371   3,371   774
Cash And Cash Equivalents [Member] | Level 2 [Member] | Corporate debt [Member]          
Marketable Securities [Line Items]          
Available-for-sale Securities 5,129   5,129   6,036
Cash And Cash Equivalents [Member] | Level 2 [Member] | Sovereign and Corporate Debt [Member]          
Marketable Securities [Line Items]          
Trading Securities 97   97   431
Marketable Securities [Member]          
Marketable Securities [Line Items]          
Available-for-sale Securities 6,097   6,097   7,955
Trading Securities 1,103   1,103   1,267
Marketable Securities [Member] | Level 2 [Member] | U.S. government and agencies [Member]          
Marketable Securities [Line Items]          
Available-for-sale Securities 3,874   3,874   5,957
Marketable Securities [Member] | Level 2 [Member] | Sovereign Debt [Member]          
Marketable Securities [Line Items]          
Trading Securities 1,103   1,103   1,267
Marketable Securities [Member] | Level 2 [Member] | Corporate debt [Member]          
Marketable Securities [Line Items]          
Available-for-sale Securities 2,223   2,223   1,998
Restricted cash and marketable securities [Member]          
Marketable Securities [Line Items]          
Available-for-sale Securities 1,308   1,308   1,427
Restricted cash and cash equivalents and time deposits 757   757   846
Restricted cash and marketable securities [Member] | Level 1 [Member] | Money Market Funds [Member]          
Marketable Securities [Line Items]          
Available-for-sale Securities $ 1,308   $ 1,308   $ 1,427