Property, Plant and Equipment (Tables)

3 Months Ended

Mar. 31, 2016

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, 2016		December 31, 2015
Land	n/a	$	3,946	$	3,744
Gathering systems	3 to 47 years	6,160,896		6,061,004
Pipelines and equipment	15 to 45 years	136,263		136,290
Assets under construction	n/a	371,358		329,887
Other	3 to 40 years	28,346		25,853
Total property, plant and equipment		6,700,809		6,556,778
Accumulated depreciation		1,760,590		1,697,999
Net property, plant and equipment		$	4,940,219	$	4,858,779