The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2(a),(d))
-URI http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227

Name:	us-gaap_CostOfGoodsAndServicesSold
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Revenue Recognition (Gathering and Treating Fees) (Details) - Natural Gas, Gathering and Treating Fees - Accounting Standards Update 2014-09 - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Natural Gas Revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cost of goods and services sold	$ 2,209		$ 5,413
Lease Operating Expense
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cost of goods and services sold		$ 909		$ 2,393