| ($ in millions) | |||||||
| At December 31: | 2013 | 2012 | |||||
| Land and land improvements | $ | 706 | $ | 747 | |||
| Buildings and building improvements | 9,680 | 9,610 | |||||
| Plant, laboratory and office equipment | 28,169 | 27,731 | |||||
| Plant and other property—gross | 38,555 | 38,088 | |||||
| Less: Accumulated depreciation | 25,576 | 25,234 | |||||
| Plant and other property—net | 12,979 | 12,854 | |||||
| Rental machines | 1,920 | 2,414 | |||||
| Less: Accumulated depreciation | 1,078 | 1,271 | |||||
| Rental machines—net | 842 | 1,142 | |||||
| Total—net | $ | 13,821 | $ | 13,996 |