v2.4.0.8
Property, Plant and Equipment
 9 Months Ended
Sep. 30, 2014
Property, Plant and Equipment [Abstract]  
Property, Plant and Equipment
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


Depreciation expense on property, plant and equipment amounted to $31.6 million, $37.5 million and $27.9 million for the year-to-date periods ended September 30, 2014, December 31, 2013, and September 30, 2013, respectively.

In December 2013, the Company recorded charges totaling $4.4 million for asset impairment, primarily due to the write down of asset values in Retail. The Company wrote down the value of these assets to the extent their carrying amounts exceeded fair value. The Company classified the significant assumptions used to determine the fair value of the impaired assets, which were not material, as Level 3 in the fair value hierarchy. 
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


Depreciation expense on railcar assets leased to others amounted to $10.5 million, $14.7 million and $11.1 million for the year-to-date periods ended September 30, 2014, December 31, 2013 and September 30, 2013, respectively.