Net Income Per Limited Partner Unit (Schedule of Net Income Per Limited Partner Unit) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions |
3 Months Ended |
8 Months Ended |
9 Months Ended |
Sep. 30, 2016 |
Sep. 30, 2015 |
Sep. 30, 2015 |
Sep. 30, 2016 |
| Schedule Of Earnings Per Unit [Line Items] |
|
|
|
|
|
| Partners' Capital Account, Distributions |
$ 20.0
|
$ 17.4
|
$ 43.5
|
|
$ 58.8
|
| Undistributed Earnings, Basic |
(17.1)
|
4.6
|
8.1
|
[1] |
(10.5)
|
| Net Income (Loss) Allocated to Limited Partners |
$ 2.9
|
$ 22.0
|
$ 51.6
|
|
$ 48.3
|
| Weighted Average Number of Shares Outstanding, Basic and Diluted |
100.6
|
100.6
|
100.6
|
|
100.6
|
| Net Income (Loss), Per Outstanding Limited Partnership and General Partnership Unit, Basic and Diluted, Net of Tax |
$ 0.03
|
$ 0.22
|
$ 0.51
|
|
$ 0.46
|
| Incentive Distribution Rights [Member] |
|
|
|
|
|
| Schedule Of Earnings Per Unit [Line Items] |
|
|
|
|
|
| Incentive Distribution, Distribution |
$ 0.1
|
$ 0.0
|
$ 0.0
|
|
$ 0.1
|
| Undistributed Earnings, Basic |
(0.1)
|
0.0
|
0.0
|
[1] |
2.2
|
| Net Income (Loss) Allocated to Limited Partners |
0.0
|
0.0
|
0.0
|
|
2.3
|
| Subordinated Units |
|
|
|
|
|
| Schedule Of Earnings Per Unit [Line Items] |
|
|
|
|
|
| Distribution Made to Limited Partner, Cash Distributions Declared |
9.3
|
8.1
|
20.3
|
|
27.4
|
| Undistributed Earnings, Basic |
(9.3)
|
2.1
|
3.4
|
[1] |
(7.3)
|
| Net Income (Loss) Allocated to Limited Partners |
$ 0.0
|
$ 10.2
|
$ 23.7
|
|
$ 20.1
|
| Weighted Average Number of Shares Outstanding, Basic and Diluted |
46.8
|
46.8
|
46.8
|
|
46.8
|
| Net Income (Loss), Per Outstanding Limited Partnership and General Partnership Unit, Basic and Diluted, Net of Tax |
$ 0.00
|
$ 0.22
|
$ 0.51
|
|
$ 0.43
|
| Common Units |
|
|
|
|
|
| Schedule Of Earnings Per Unit [Line Items] |
|
|
|
|
|
| Distribution Made to Limited Partner, Cash Distributions Declared |
$ 10.6
|
$ 9.3
|
$ 23.2
|
|
$ 31.3
|
| Undistributed Earnings, Basic |
(7.7)
|
2.5
|
4.7
|
[1] |
(5.4)
|
| Net Income (Loss) Allocated to Limited Partners |
$ 2.9
|
$ 11.8
|
$ 27.9
|
|
$ 25.9
|
| Weighted Average Number of Shares Outstanding, Basic and Diluted |
53.8
|
53.8
|
53.8
|
|
53.8
|
| Net Income (Loss), Per Outstanding Limited Partnership and General Partnership Unit, Basic and Diluted, Net of Tax |
$ 0.05
|
$ 0.22
|
$ 0.52
|
|
$ 0.48
|
|
|