COMMITMENTS AND CONTINGENCIES (Narrative) (Details) $ in Millions, $ in Millions |
6 Months Ended | |||
|---|---|---|---|---|
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Jun. 30, 2018
USD ($)
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Jun. 30, 2018
CAD ($)
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Jan. 01, 2018
USD ($)
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Dec. 31, 2017
USD ($)
|
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| Loss Contingencies [Line Items] | Ìý | Ìý | Ìý | Ìý |
| Loans to and accounts receivable from the Canadian Entities | $ 0.0 | Ìý | $ 51.6 | $ 51.6 |
| Cash contribution | Ìý | $ 19.0 | Ìý | Ìý |
| Michigan Electricity Matters [Member] | Ìý | Ìý | Ìý | Ìý |
| Loss Contingencies [Line Items] | Ìý | Ìý | Ìý | Ìý |
| Loss Contingency Accrual | 10.8 | Ìý | Ìý | $ 13.0 |
| Loss Contingency Accrual, Period Increase (Decrease) | $ 2.2 | Ìý | Ìý | Ìý |
| X | ||||||||||
- Definition Cash Contribution No definition available.
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| X | ||||||||||
- Definition Loans to and accounts receivables from the Canadian Entities No definition available.
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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| X | ||||||||||
- Definition Amount of loss contingency liability. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of increase (decrease) in loss contingency liability. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Details
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