Revenue from Contracts with Customers (Contract with Customer, Asset and Liability) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Contract liability	$ 5,625	$ 7,061
Mid-Stream [Member]
Disaggregation of Revenue [Line Items]
Contract assets	9,695	12,921
Change in contract assets	(3,226)
Contract liability	5,625	7,061
Change in contract liabilities	(1,436)
Contract asset (liabilities), net	4,070	$ 5,860
Change in contract assets (liabilities)	$ (1,790)