CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN PARTNERS' CAPITAL (Unaudited) - USD ($) $ in Millions	Total	Accumulated Other Comp Income (Loss)	Limited Partner Common Units	General Partner	Partners' Capital
Beginning balance at Dec. 31, 2017	$ 4,724.8	$ (81.0)	$ 4,713.1	$ 92.7
Add (deduct):
Net income	97.2		95.3	1.9
Distributions paid	(25.6)		(25.1)	(0.5)
Other comprehensive income, net of tax	0.9	0.9
Ending balance at Mar. 31, 2018	4,784.5	(80.1)	4,770.7	93.9
Add (deduct):
Cumulative effect adjustment from the implementation of ASC 606	(12.8)		$ (12.6)	$ (0.2)
Beginning balance at Dec. 31, 2018	4,861.9	(85.2)			$ 4,947.1
Add (deduct):
Net income	108.1				108.1
Distributions paid	(25.6)				(25.6)
Other comprehensive income, net of tax	0.8	0.8
Ending balance at Mar. 31, 2019	$ 4,945.2	$ (84.4)			$ 5,029.6