Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2018

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment [Table Text Block]

Depreciation is calculated primarily using the straight-line method over the following estimated useful lives:

Pipelines and related facilities	10 – 31 years
Storage and terminal facilities	10 – 25 years
Natural gas gathering and processing facilities	10 – 31 years
Trucking equipment and other	3 – 7 years
Office property and equipment	3 – 31 years

Property, plant and equipment consists of the following (in thousands):

	December 31,
	2018			2017
Land	$	308,166		$	273,168
Pipelines and related facilities	1,023,502			926,799
Storage and terminal facilities	1,247,115			1,111,001
Natural gas gathering and processing facilities	1,055,305			940,130
Linefill	27,972			25,747
Trucking equipment and other	45,567			45,162
Office property and equipment	69,498			63,052
Construction-in-progress	288,104			374,914
Property, plant and equipment, gross	4,065,229			3,759,973
Accumulated depreciation	(607,903		)	(444,842		)
Property, plant and equipment, net	$	3,457,326		$	3,315,131