Property, Plant and Equipment

3 Months Ended

Mar. 31, 2019

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

Property, Plant and Equipment

The components of Property, plant and equipment, net are as follows:

(in thousands)	March 31, 2019		December 31, 2018		March 31, 2018
Land	$	39,552	$	29,739	$	29,915
Land improvements and leasehold improvements	82,681		68,826		69,320
Buildings and storage facilities	337,631		284,998		285,084
Machinery and equipment	481,454		393,640		377,563
Construction in progress	151,895		102,394		15,116
	1,093,213		879,597		776,998
Less: accumulated depreciation	421,408		402,886		383,235
	$	671,805	$	476,711	$	393,763

Capitalized interest totaled $1.1 million and $1.7 million for the three months ended March 31, 2019 and year-ended December 31, 2018, respectively.

Depreciation expense on property, plant and equipment was $17.9 million and $11.6 million for the three months ended March 31, 2019 and 2018, respectively.

Rail Group Assets

The components of Rail Group assets leased to others are as follows:

(in thousands)	March 31, 2019		December 31, 2018		March 31, 2018
Rail Group assets leased to others	$	660,747	$	640,349	$	577,678
Less: accumulated depreciation	123,118		118,564		115,425
	$	537,629	$	521,785	$	462,253

Depreciation expense on Rail Group assets leased to others amounted to $6.7 million and $6.2 million for the three months ended March 31, 2019 and 2018, respectively.