Unitholders' Equity and Partnership Distributions Partnership Distributions (Details) - Cash Distribution [Member] - $ / shares	3 Months Ended			6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Jun. 30, 2019
Distribution Made to Limited Partner [Line Items]
Distribution Made to Limited Partner, Distributions Declared, Per Unit	$ 0.38	$ 0.51
Distribution Made to Limited Partner, Declaration Date	Apr. 25, 2019	Jan. 30, 2019	Jul. 28, 2019
Distribution Made to Limited Partner, Date of Record	May 13, 2019	Feb. 19, 2019
Distribution Made to Limited Partner, Distribution Date	May 20, 2019	Feb. 25, 2019	Aug. 21, 2019
Distribution Made to Limited Partner, Distribution Date, Period after Quarter End				60 days