Revenue from Contracts with Customers (Contract with Customer, Asset and Liability) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Contract liability	$ 6,343	$ 7,061
Mid-Stream [Member]
Disaggregation of Revenue [Line Items]
Contract assets	11,395	12,921
Change in contract assets	(1,526)
Contract liability	6,343	7,061
Change in contract liabilities	(718)
Contract asset (liabilities), net	5,052	$ 5,860
Change in contract assets (liabilities)	$ (808)