| Components of property, plant and equipment |
The components of property, plant and equipment are as follows: | | | | | | | | | | | | | (in thousands) | September 30,
2014 | | December 31,
2013 | | September 30,
2013 | Land | $ | 22,415 |
| | $ | 21,801 |
| | $ | 23,348 |
| Land improvements and leasehold improvements | 68,976 |
| | 67,153 |
| | 67,262 |
| Buildings and storage facilities | 238,664 |
| | 231,976 |
| | 224,913 |
| Machinery and equipment | 320,648 |
| | 308,215 |
| | 299,874 |
| Software | 55,791 |
| | 13,351 |
| | 13,558 |
| Construction in progress | 28,260 |
| | 48,135 |
| | 54,713 |
| | 734,754 |
| | 690,631 |
| | 683,668 |
| Less: accumulated depreciation and amortization | 332,954 |
| | 303,173 |
| | 303,294 |
| | $ | 401,800 |
| | $ | 387,458 |
| | $ | 380,374 |
|
|
| Components of railcar assets leased to others |
The components of Railcar assets leased to others are as follows: | | | | | | | | | | | | | (in thousands) | September 30,
2014 | | December 31,
2013 | | September 30,
2013 | Railcar assets leased to others | $ | 330,318 |
| | $ | 317,750 |
| | $ | 309,360 |
| Less: accumulated depreciation | 84,469 |
| | 77,129 |
| | 76,336 |
| | $ | 245,849 |
| | $ | 240,621 |
| | $ | 233,024 |
|
|