|
Marketable Securities (current and non-current) (Details) (USD $)
In Millions, unless otherwise specified
|
Mar. 31, 2015
|
Dec. 31, 2014
|
| Marketable securities classification |
|
|
| Current marketable securities |
$ 1,018 |
$ 626 |
| Non-current marketable securities |
13 |
828 |
| Total marketable securities |
1,031 |
1,454 |
| U.S. government agency securities |
|
|
| Marketable securities classification |
|
|
| Current marketable securities |
67 |
67 |
| Non-current marketable securities |
1 |
41 |
| Foreign government agency securities |
|
|
| Marketable securities classification |
|
|
| Current marketable securities |
60 |
75 |
| Non-current marketable securities |
0 |
20 |
| Corporate debt securities |
|
|
| Marketable securities classification |
|
|
| Current marketable securities |
551 |
241 |
| Non-current marketable securities |
0 |
378 |
| Commercial paper |
|
|
| Marketable securities classification |
|
|
| Current marketable securities |
27 |
0 |
| Certificates of deposit/time deposits |
|
|
| Marketable securities classification |
|
|
| Current marketable securities |
24 |
41 |
| U.S. treasury securities |
|
|
| Marketable securities classification |
|
|
| Non-current marketable securities |
0 |
38 |
| U.S. municipal securities |
|
|
| Marketable securities classification |
|
|
| Current marketable securities |
3 |
0 |
| Non-current marketable securities |
12 |
15 |
| Asset-backed securities |
|
|
| Marketable securities classification |
|
|
| Current marketable securities |
286 |
202 |
| Non-current marketable securities |
0 |
336 |
| Asset-backed securities Automobile loan related |
|
|
| Marketable securities classification |
|
|
| Current marketable securities |
167 |
122 |
| Non-current marketable securities |
0 |
160 |
| Asset-backed securities Credit card related |
|
|
| Marketable securities classification |
|
|
| Current marketable securities |
66 |
59 |
| Non-current marketable securities |
0 |
103 |
| Asset-backed securities Equipment lease related |
|
|
| Marketable securities classification |
|
|
| Current marketable securities |
7 |
21 |
| Non-current marketable securities |
0 |
27 |
| Asset-backed securities Other asset-backed securities |
|
|
| Marketable securities classification |
|
|
| Current marketable securities |
46 |
0 |
| Non-current marketable securities |
$ 0 |
$ 46 |