Partners' Capital and Distributions (Schedule Of Distributions) (Details) - USD ($) $ / shares in Units, $ in Thousands							6 Months Ended	12 Months Ended
	May 15, 2019	Feb. 14, 2019	Nov. 14, 2018	Aug. 14, 2018	May 15, 2018	Feb. 14, 2018	Jun. 30, 2019	Dec. 31, 2018
Distribution Made to Limited Partner [Line Items]
Cash distribution per unit (in dollars per share)		$ 0.9975	$ 0.9775	$ 0.9575	$ 0.9375	$ 0.9200		$ 3.7925
Total Cash Distribution to Limited Partners		$ 227,832	$ 223,061	$ 218,497	$ 213,933	$ 209,940		$ 865,431
Scenario, Forecast
Distribution Made to Limited Partner [Line Items]
Cash distribution per unit (in dollars per share)	$ 1.0050						$ 2.0025
Total Cash Distribution to Limited Partners	$ 229,545						$ 457,377