CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN PARTNERS' CAPITAL (Unaudited) - USD ($) $ in Millions	Total	Accumulated Other Comp Income (Loss)	General Partner	Limited Partner Common Units
Beginning balance at Dec. 31, 2015	$ 4,326.7	$ (84.3)	$ 84.8	$ 4,326.2
Add (deduct):
Net income	214.0		4.3	209.7
Distributions paid	(76.7)		(1.5)	(75.2)
Other comprehensive income, net of tax	4.1	4.1
Ending balance at Sep. 30, 2016	4,468.1	(80.2)	87.6	4,460.7
Beginning balance at Dec. 31, 2016	4,530.9	(80.1)	88.8	4,522.2
Add (deduct):
Net income	212.8		4.2	208.6
Distributions paid	(76.7)		(1.5)	(75.2)
Other comprehensive income, net of tax	1.2	1.2
Ending balance at Sep. 30, 2017	$ 4,668.2	$ (78.9)	$ 91.5	$ 4,655.6