Net Income Per Limited Partner Unit - Schedule of Allocation of Net Income to Arrive at Net Income Per Limited Partner Unit (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Limited Partners Capital Account [Line Items]
Net income	$ 72.3	$ 58.8	$ 66.3	$ 68.0	$ 72.5	$ 90.6	$ 60.7	$ 49.1	$ 265.4	$ 272.9	$ 148.9
Net Income Attributable to the Predecessors									0.0	39.3	124.1
Net income attributable to noncontrolling interests									20.5	66.5	11.4
Net income attributable to the Partnership	$ 69.5	$ 56.3	$ 63.8	$ 55.3	$ 57.0	$ 54.3	$ 32.2	$ 23.6	244.9	167.1	13.4
Partner distribution declared									203.2	117.4	14.4
Income in excess of distributions									41.7	49.7	(1.0)
General Partner
Limited Partners Capital Account [Line Items]
Net income attributable to the Partnership									25.0	5.0	0.3
Partner distribution declared									24.2	4.0	0.3
Income in excess of distributions									0.8	1.0	0.0
Limited Partners' Common Units
Limited Partners Capital Account [Line Items]
Net income attributable to the Partnership									134.4	85.5	6.5
Partner distribution declared									109.8	60.1	7.0
Income in excess of distributions									24.6	25.4	(0.5)
Limited Partner's Subordinated Units
Limited Partners Capital Account [Line Items]
Net income attributable to the Partnership									85.5	76.6	6.6
Partner distribution declared									69.2	53.3	7.1
Income in excess of distributions									$ 16.3	$ 23.3	$ (0.5)