Property, Plant and Equipment (Tables)

3 Months Ended

Mar. 31, 2018

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment Table

A summary of the historical cost of property, plant and equipment is as follows:

thousands	Estimated Useful Life	March 31, 2018		December 31, 2017
Land	n/a	$	4,449	$	4,450
Gathering systems and processing complexes	3 to 47 years	7,305,279		7,114,701
Pipelines and equipment	15 to 45 years	137,765		137,644
Assets under construction	n/a	794,012		577,914
Other	3 to 40 years	30,578		36,393
Total property, plant and equipment		8,272,083		7,871,102
Accumulated depreciation		2,208,536		2,140,211
Net property, plant and equipment		$	6,063,547	$	5,730,891