Stockholders' Equity Accumulated Other Comprehensive Loss (Details) - USD ($)
$ in Millions |
3 Months Ended |
Mar. 31, 2016 |
Mar. 31, 2015 |
| Accumulated Other Comprehensive Loss, Net of Tax [Roll Forward] |
|
|
| Balance at beginning of period |
$ (8,036)
|
|
| Other comprehensive income (loss), net of tax |
(38)
|
$ 751
|
| Balance at end of period |
(8,054)
|
|
| Foreign currency translation adjustments [Member] |
|
|
| Accumulated Other Comprehensive Loss, Net of Tax [Roll Forward] |
|
|
| Balance at beginning of period |
(2,034)
|
(1,064)
|
| Other comprehensive income (loss), before reclassifications adjustment, net of tax |
71
|
22
|
| Reclassification adjustment, net of tax |
(5)
|
170
|
| Other comprehensive income (loss), net of tax |
66
|
192
|
| Other comprehensive income (loss) attributable to noncontrolling interests, net of tax |
19
|
(9)
|
| Balance at end of period |
(1,949)
|
(881)
|
| Defined benefit plans, net [Member] |
|
|
| Accumulated Other Comprehensive Loss, Net of Tax [Roll Forward] |
|
|
| Balance at beginning of period |
(5,999)
|
(7,006)
|
| Other comprehensive income (loss), before reclassifications adjustment, net of tax |
(148)
|
488
|
| Reclassification adjustment, net of tax |
26
|
66
|
| Other comprehensive income (loss), net of tax |
(122)
|
554
|
| Balance at end of period |
$ (6,121)
|
$ (6,452)
|