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 |
9 Months Ended |
Sep. 30, 2015 |
Sep. 30, 2015 |
| Schedule Of Earnings Per Unit [Line Items] |
|
|
|
| Incentive Distribution, Distribution |
$ 0.0
|
$ 0.0
|
[1] |
| Partners' Capital Account, Distributions |
17.4
|
43.5
|
|
| Undistributed Earnings, Basic |
4.6
|
8.1
|
[1] |
| Net Income (Loss) Allocated to Limited Partners |
$ 22.0
|
$ 51.6
|
[1] |
| Weighted Average Number of Shares Outstanding, Basic and Diluted |
100.6
|
100.6
|
|
| Net Income (Loss), Per Outstanding Limited Partnership and General Partnership Unit, Basic and Diluted, Net of Tax |
$ 0.22
|
$ 0.51
|
|
| Incentive Distribution Rights [Member] |
|
|
|
| Schedule Of Earnings Per Unit [Line Items] |
|
|
|
| Incentive Distribution, Distribution |
$ 0.0
|
$ 0.0
|
|
| Undistributed Earnings, Basic |
0.0
|
0.0
|
|
| Net Income (Loss) Allocated to Limited Partners |
$ 0.0
|
$ 0.0
|
|
| Weighted Average Number of Shares Outstanding, Basic and Diluted |
0.0
|
0.0
|
|
| Net Income (Loss), Per Outstanding Limited Partnership and General Partnership Unit, Basic and Diluted, Net of Tax |
$ 0.00
|
$ 0.00
|
|
| Subordinated Units [Member] |
|
|
|
| Schedule Of Earnings Per Unit [Line Items] |
|
|
|
| Distribution Made to Limited Partner, Cash Distributions Declared |
$ 8.1
|
$ 20.3
|
[1] |
| Undistributed Earnings, Basic |
2.1
|
3.4
|
|
| Net Income (Loss) Allocated to Limited Partners |
$ 10.2
|
$ 23.7
|
|
| Weighted Average Number of Shares Outstanding, Basic and Diluted |
46.8
|
46.8
|
|
| Net Income (Loss), Per Outstanding Limited Partnership and General Partnership Unit, Basic and Diluted, Net of Tax |
$ 0.22
|
$ 0.51
|
|
| Common Units [Member] |
|
|
|
| Schedule Of Earnings Per Unit [Line Items] |
|
|
|
| Distribution Made to Limited Partner, Cash Distributions Declared |
$ 9.3
|
$ 23.2
|
[1] |
| Undistributed Earnings, Basic |
2.5
|
4.7
|
|
| Net Income (Loss) Allocated to Limited Partners |
$ 11.8
|
$ 27.9
|
|
| Weighted Average Number of Shares Outstanding, Basic and Diluted |
53.8
|
53.8
|
|
| Net Income (Loss), Per Outstanding Limited Partnership and General Partnership Unit, Basic and Diluted, Net of Tax |
$ 0.22
|
$ 0.52
|
|
|
|