Partners' Capital, Mezzanine Capital and Distributions (Distributions Paid-in-kind) (Details) - Class A Convertible Preferred Stock Units - USD ($) $ in Thousands						6 Months Ended
	May 15, 2019	Feb. 14, 2019	Nov. 14, 2018	Aug. 14, 2018	May 15, 2018	Jun. 30, 2019
Temporary Equity [Line Items]
Date Issued	May 15, 2019	Feb. 14, 2019	Nov. 14, 2018	Aug. 14, 2018	May 15, 2018
Number of Units (in units)	364,180	534,576	523,132	511,934	500,976	898,756
Total Amount	$ 12,277	$ 18,021	$ 17,635	$ 17,527	$ 16,888	$ 30,298