Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2017

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment Table

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

		December 31,
thousands	Estimated Useful Life	2017		2016
Land	n/a	$	4,450	$	4,012
Gathering systems and processing complexes	3 to 47 years	7,114,701		6,462,053
Pipelines and equipment	15 to 45 years	137,644		139,646
Assets under construction	n/a	577,914		226,626
Other	3 to 40 years	36,393		29,605
Total property, plant and equipment		7,871,102		6,861,942
Accumulated depreciation		2,140,211		1,812,010
Net property, plant and equipment		$	5,730,891	$	5,049,932