Transactions With Affiliates (Narrative) (Details) - USD ($)
$ in Millions |
11 Months Ended |
12 Months Ended |
|
Dec. 31, 2015 |
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
Dec. 05, 2014 |
| Related Party Transaction [Line Items] |
|
|
|
|
|
| Interest Expense, Long-term Debt |
|
$ 35.1
|
|
|
|
| Allowance for Funds Used During Construction, Capitalized Interest |
|
$ 9.2
|
|
|
|
| Short-term Debt, Weighted Average Interest Rate |
1.21%
|
1.21%
|
|
|
|
| Interest Expense, Short-term Borrowings |
|
$ 0.9
|
|
|
|
| Accounts Receivable |
$ 149.4
|
149.4
|
|
|
|
| Line of Credit Facility, Maximum Borrowing Capacity |
2,600.0
|
2,600.0
|
|
|
|
| Default Provision Floor |
50.0
|
50.0
|
|
|
|
| Short-term borrowings-affiliated |
42.1
|
42.1
|
|
|
|
| Distribution to Parent |
|
687.3
|
|
|
|
| Transportation and Storage Services |
|
|
|
|
|
| Related Party Transaction [Line Items] |
|
|
|
|
|
| Accounts Receivable |
8.9
|
8.9
|
|
|
|
| Predecessor |
|
|
|
|
|
| Related Party Transaction [Line Items] |
|
|
|
|
|
| Interest Expense, Long-term Debt |
|
|
$ 61.6
|
$ 40.6
|
|
| Allowance for Funds Used During Construction, Capitalized Interest |
|
|
$ 2.7
|
6.8
|
|
| Short-term Debt, Weighted Average Interest Rate |
|
|
0.70%
|
|
|
| Interest Expense, Short-term Borrowings |
|
|
$ 3.1
|
4.1
|
|
| Accounts Receivable |
|
|
153.8
|
|
|
| Short-term borrowings-affiliated |
|
|
247.3
|
|
|
| Distribution to Parent |
|
|
0.0
|
$ 113.0
|
|
| Predecessor | Transportation and Storage Services |
|
|
|
|
|
| Related Party Transaction [Line Items] |
|
|
|
|
|
| Accounts Receivable |
|
|
28.8
|
|
|
| Money Pool |
|
|
|
|
|
| Related Party Transaction [Line Items] |
|
|
|
|
|
| Accounts Receivable |
140.5
|
140.5
|
|
|
|
| Line of Credit Facility, Maximum Borrowing Capacity |
750.0
|
750.0
|
|
|
|
| Money Pool | Predecessor |
|
|
|
|
|
| Related Party Transaction [Line Items] |
|
|
|
|
|
| Accounts Receivable |
|
|
$ 125.0
|
|
|
| Revolving Credit Facility |
|
|
|
|
|
| Related Party Transaction [Line Items] |
|
|
|
|
|
| Line of Credit Facility, Maximum Borrowing Capacity |
500.0
|
500.0
|
|
|
$ 1,500.0
|
| Notes Due 2020 |
|
|
|
|
|
| Related Party Transaction [Line Items] |
|
|
|
|
|
| Line of Credit Facility, Maximum Borrowing Capacity |
$ 2,300.0
|
$ 2,300.0
|
|
|
|
| Debt Instrument, Interest Rate, Stated Percentage |
4.70%
|
4.70%
|
|
|
|
| Debt Instrument, Maturity Date |
|
Dec. 31, 2020
|
|
|
|
| Columbia OpCo |
|
|
|
|
|
| Related Party Transaction [Line Items] |
|
|
|
|
|
| Reimbursement of Preformation Capital |
$ 500.0
|
|
|
|
|
| London Interbank Offered Rate (LIBOR) |
|
|
|
|
|
| Related Party Transaction [Line Items] |
|
|
|
|
|
| Debt Instrument, Basis Spread on Variable Rate |
|
1.00%
|
|
|
|