CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN PARTNERS' CAPITAL (Unaudited) - USD ($) $ in Millions	Total	Accumulated Other Comp (Loss) Income	Partners' Capital
Beginning balance at Dec. 31, 2018	$ 4,861.9	$ (85.2)	$ 4,947.1
Add (deduct):
Net income	226.3		226.3
Distributions paid	(76.7)		(76.7)
Other comprehensive income, net of tax	3.6	3.6
Ending balance at Sep. 30, 2019	5,015.1	(81.6)	5,096.7
Beginning balance at Jun. 30, 2019	4,997.4	(82.4)	5,079.8
Add (deduct):
Net income	42.5		42.5
Distributions paid	(25.6)		(25.6)
Other comprehensive income, net of tax	0.8	0.8
Ending balance at Sep. 30, 2019	5,015.1	(81.6)	5,096.7
Beginning balance at Dec. 31, 2019	5,059.5	(81.1)	5,140.6
Add (deduct):
Net income	175.6		175.6
Other comprehensive income, net of tax	2.9	2.9
Ending balance at Sep. 30, 2020	5,238.0	(78.2)	5,316.2
Beginning balance at Jun. 30, 2020	5,204.9	(79.3)	5,284.2
Add (deduct):
Net income	32.0		32.0
Other comprehensive income, net of tax	1.1	1.1
Ending balance at Sep. 30, 2020	$ 5,238.0	$ (78.2)	$ 5,316.2