Partners' Capital and Distributions (Distributions Made to Limited Partner) (Details) - USD ($) $ / shares in Units, $ in Millions													12 Months Ended
	Nov. 14, 2022	Aug. 12, 2022	May 13, 2022	Feb. 14, 2022	Nov. 12, 2021	Aug. 13, 2021	May 14, 2021	Feb. 12, 2021	Nov. 13, 2020	Aug. 14, 2020	May 15, 2020	Feb. 14, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Partners' Capital Notes [Abstract]
Per Unit Distribution Amount (in dollars per share)	$ 1.0475	$ 1.0375	$ 1.0375	$ 1.0375	$ 1.0375	$ 1.0275	$ 1.0275	$ 1.0275	$ 1.0275	$ 1.0275	$ 1.0275	$ 1.0275	$ 4.1600	$ 4.1200	$ 4.1100
Total Distribution	$ 214.7	$ 215.2	$ 219.5	$ 220.6	$ 221.4	$ 226.6	$ 229.0	$ 229.4	$ 229.9	$ 231.2	$ 231.2	$ 234.8	$ 870.0	$ 906.4	$ 927.1