Partners' Capital, Mezzanine Capital and Distributions (Preferred Cash Distributions Paid) (Details) - Preferred Unitholders - Class A Convertible Preferred Stock Units - USD ($) $ / shares in Units, $ in Thousands	May 15, 2020	Feb. 14, 2020	Nov. 14, 2019	Aug. 14, 2019	May 15, 2019
Temporary Equity [Line Items]
Date Paid		Feb. 14, 2020	Nov. 14, 2019	Aug. 14, 2019	May 15, 2019
Per Unit Amount (in dollars per unit)		$ 0.7374	$ 0.7374	$ 0.7374	$ 0.2458
Total Amount		$ 18,684	$ 18,684	$ 18,684	$ 6,138
Forecast | Subsequent Event
Temporary Equity [Line Items]
Date Paid	May 15, 2020
Per Unit Amount (in dollars per unit)	$ 0.7374
Total Amount	$ 18,684