Partners' Capital (Summary Of Quarterly Cash Distributions Declarations, Payments And Scheduled Payments) (Details) - $ / shares	3 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015
Partners' Capital [Abstract]
Declaration Date	Jan. 18, 2018	Oct. 19, 2017	Jul. 20, 2017	Apr. 20, 2017	Jan. 23, 2017	Oct. 20, 2016	Jul. 20, 2016	Apr. 21, 2016	Jan. 21, 2016	Oct. 22, 2015
Record Date	Feb. 02, 2018	Nov. 03, 2017	Aug. 04, 2017	May 05, 2017	Feb. 03, 2017	Nov. 04, 2016	Aug. 05, 2016	May 06, 2016	Feb. 05, 2016	Nov. 06, 2015
Payment Date	Feb. 09, 2018	Nov. 10, 2017	Aug. 11, 2017	May 15, 2017	Feb. 14, 2017	Nov. 14, 2016	Aug. 12, 2016	May 13, 2016	Feb. 12, 2016	Nov. 13, 2015
Quarterly Distribution	$ 0.4700	$ 0.4600	$ 0.4500	$ 0.4400	$ 0.4300	$ 0.4200	$ 0.4100	$ 0.4050	$ 0.4025	$ 0.4000