Transactions With Affiliates (Narrative) (Details) - USD ($)
$ in Millions |
3 Months Ended |
5 Months Ended |
6 Months Ended |
|
|
Jun. 30, 2015 |
Jun. 30, 2014 |
Jun. 30, 2015 |
Jun. 30, 2015 |
Jun. 30, 2014 |
Dec. 31, 2014 |
Dec. 05, 2014 |
| Related Party Transaction [Line Items] |
|
|
|
|
|
|
|
| Interest Expense, Long-term Debt |
$ 7.5
|
|
|
$ 19.7
|
|
|
|
| Allowance for Funds Used During Construction, Capitalized Interest |
$ 1.4
|
|
|
$ 2.4
|
|
|
|
| Short-term Debt, Weighted Average Interest Rate |
1.21%
|
|
1.21%
|
1.21%
|
|
|
|
| Interest Expense, Short-term Borrowings |
$ 0.2
|
|
|
$ 0.4
|
|
|
|
| Accounts receivable-affiliated |
656.7
|
|
$ 656.7
|
656.7
|
|
|
|
| Revolving credit facility |
2,600.0
|
|
2,600.0
|
2,600.0
|
|
|
|
| Default Provision Floor |
50.0
|
|
50.0
|
50.0
|
|
|
|
| Short-term Debt |
20.0
|
|
20.0
|
20.0
|
|
|
|
| Short-term borrowings-affiliated |
67.1
|
|
67.1
|
67.1
|
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|
|
| Transportation and Storage Services |
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|
|
|
|
|
| Related Party Transaction [Line Items] |
|
|
|
|
|
|
|
| Accounts receivable-affiliated |
13.4
|
|
13.4
|
13.4
|
|
|
|
| Predecessor [Member] |
|
|
|
|
|
|
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| Related Party Transaction [Line Items] |
|
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|
|
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| Interest Expense, Long-term Debt |
|
$ 13.9
|
|
|
$ 26.1
|
|
|
| Allowance for Funds Used During Construction, Capitalized Interest |
|
$ 2.0
|
|
|
$ 3.2
|
|
|
| Short-term Debt, Weighted Average Interest Rate |
|
0.64%
|
|
|
0.64%
|
|
|
| Interest Expense, Short-term Borrowings |
|
$ 0.7
|
|
|
$ 1.8
|
|
|
| Accounts receivable-affiliated |
|
|
|
|
|
$ 153.8
|
|
| Short-term Debt |
|
|
|
|
|
0.0
|
|
| Short-term borrowings-affiliated |
|
|
|
|
|
247.3
|
|
| Predecessor [Member] | Transportation and Storage Services |
|
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|
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| Related Party Transaction [Line Items] |
|
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|
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| Accounts receivable-affiliated |
|
|
|
|
|
28.8
|
|
| Columbia OpCo |
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|
|
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| Related Party Transaction [Line Items] |
|
|
|
|
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|
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| Reimbursement of Preformation Capital |
|
|
500.0
|
|
|
|
|
| Money Pool |
|
|
|
|
|
|
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| Related Party Transaction [Line Items] |
|
|
|
|
|
|
|
| Accounts receivable-affiliated |
643.2
|
|
643.2
|
643.2
|
|
|
|
| Revolving credit facility |
750.0
|
|
750.0
|
750.0
|
|
|
|
| Money Pool | Predecessor [Member] |
|
|
|
|
|
|
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| Related Party Transaction [Line Items] |
|
|
|
|
|
|
|
| Accounts receivable-affiliated |
|
|
|
|
|
$ 125.0
|
|
| Revolving Credit Facility |
|
|
|
|
|
|
|
| Related Party Transaction [Line Items] |
|
|
|
|
|
|
|
| Revolving credit facility |
$ 500.0
|
|
$ 500.0
|
$ 500.0
|
|
|
$ 1,500.0
|
| Notes Due 2016 [1] |
|
|
|
|
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| Related Party Transaction [Line Items] |
|
|
|
|
|
|
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| Debt Instrument, Maturity Date |
|
|
|
Dec. 31, 2016
|
|
|
|
| London Interbank Offered Rate (LIBOR) |
|
|
|
|
|
|
|
| Related Party Transaction [Line Items] |
|
|
|
|
|
|
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| Basis Spread on Variable Rate |
|
|
|
1.00%
|
|
|
|
| London Interbank Offered Rate (LIBOR) | Notes Due 2016 [1] |
|
|
|
|
|
|
|
| Related Party Transaction [Line Items] |
|
|
|
|
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|
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| Basis Spread on Variable Rate |
|
|
|
1.50%
|
|
|
|