Note 11. Property, Plant and Equipment - Net
| December 31, | |||||||
| 2013 | 2012 | ||||||
| Land and improvements | $ | 376 | $ | 367 | |||
| Machinery and equipment | 10,437 | 10,023 | |||||
| Buildings and improvements | 3,157 | 3,045 | |||||
| Construction in progress | 647 | 592 | |||||
| 14,617 | 14,027 | ||||||
| Less—Accumulated depreciation | (9,339) | (9,026) | |||||
| $ | 5,278 | $ | 5,001 | ||||
Depreciation expense was $670, $660 and $699 million in 2013, 2012 and 2011, respectively.