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Acquisitions - Chanarambie/Viking (Details) $ in Millions | 1 Months Ended | 3 Months Ended |  |
--- | --- | --- | --- | ---
Apr. 30, 2015 USD ($) MW | Jun. 30, 2015 USD ($) | Sep. 30, 2016 USD ($) | Dec. 31, 2015 USD ($)
Liabilities Assumed [Abstract] |  |  |  |  |
Power Purchase Agreements - Non-Current Liability |  |  |  | $ 119.8 | $ 138.1
Goodwill |  |  |  | 130.6 | 130.6
Power Purchase Agreements - Current Liability |  |  |  | $ 24.3 | $ 23.3
Chanarambie/Viking [Member] |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |
Percentage of Voting Interests Acquired |  | 100.00% |  |  |
Name of Acquired Entity |  | Chanarambie/Viking |  |  |
Payments to Acquire Business |  | $ 48.0 |  |  |
Generating Capacity (MW) | MW |  | 97.5 |  |  |
Assets Acquired [Abstract] |  |  |  |  |
Current Assets |  | $ 4.8 |  |  |
Property, Plant and Equipment |  | 103.0 |  |  |
Other Non-Current Assets | [1] | 1.0 |  |  |
Total Assets Acquired |  | 108.8 |  |  |
Liabilities Assumed [Abstract] |  |  |  |  |
Current Liabilities | [2] | 6.7 |  |  |
Power Purchase Agreements - Non-Current Liability |  | 49.0 |  |  |
Non-Current Liabilities |  | 5.1 |  |  |
Total Liabilities Assumed |  | 60.8 |  |  |
Net Identifiable Assets Acquired |  | 48.0 |  |  |
Goodwill |  | 0.3 |  |  |
Tax Deductible Goodwill |  | 0.0 |  |  |
Power Purchase Agreements - Current Liability |  | $ 5.9 |  |  |
Acquisition Related Costs |  |  | $ 0.2 |  |
Chanarambie/Viking [Member] | Chanarambie/Viking PPA (expires 2018) [Member] |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |
Generating Capacity (MW) | MW |  | 12 |  |  |
Chanarambie/Viking [Member] | Chanarambie/Viking PPA (expires 2023) [Member] |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |
Generating Capacity (MW) | MW |  | 85.5 |  |  |
[1] | Included in Other Non-Current Assets was $0.3 million of goodwill. For tax purposes, the purchase price allocation resulted in no allocation to goodwill.
[2] | Current Liabilities included $5.9 million related to the current portion of PPAs.

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