CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN PARTNERS' CAPITAL (Unaudited) - USD ($) $ in Millions	Total	Accumulated Other Comprehensive (Loss) Income	Partners' Capital
Beginning balance at Dec. 31, 2020	$ 5,249.1	$ (79.8)	$ 5,328.9
Add (deduct):
Net income	239.8		239.8
Other comprehensive income, net of tax	1.6	1.6
Ending balance at Sep. 30, 2021	5,490.5	(78.2)	5,568.7
Beginning balance at Jun. 30, 2021	5,434.5	(78.7)	5,513.2
Add (deduct):
Net income	55.5		55.5
Other comprehensive income, net of tax	0.5	0.5
Ending balance at Sep. 30, 2021	5,490.5	(78.2)	5,568.7
Beginning balance at Dec. 31, 2021	5,469.1	(72.6)	5,541.7
Add (deduct):
Net income	230.3		230.3
Other comprehensive income, net of tax	1.8	1.8
Ending balance at Sep. 30, 2022	5,701.2	(70.8)	5,772.0
Beginning balance at Jun. 30, 2022	5,650.2	(71.5)	5,721.7
Add (deduct):
Net income	50.3		50.3
Other comprehensive income, net of tax	0.7	0.7
Ending balance at Sep. 30, 2022	$ 5,701.2	$ (70.8)	$ 5,772.0