Partners' Capital, Mezzanine Capital and Distributions (Distributions Paid-in-kind) (Details) - Class A Convertible Preferred Stock Units - USD ($) $ in Thousands						3 Months Ended	9 Months Ended
	May 15, 2019	Feb. 14, 2019	Nov. 14, 2018	Aug. 14, 2018	May 15, 2018	Mar. 31, 2019	Sep. 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	364,180	898,756
Total Amount	$ 12,277	$ 18,021	$ 17,635	$ 17,527	$ 16,888		$ 30,298