Variable Interest Entities (Details) $ in Millions |
3 Months Ended | ||
|---|---|---|---|
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Mar. 31, 2016
USD ($)
MW
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Mar. 31, 2015
USD ($)
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Dec. 31, 2015
USD ($)
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| Variable interest entities | |||
| Equity investment in ATC | $ 1,422.5 | $ 1,380.9 | |
| ATC | |||
| Variable interest entities | |||
| Ownership interest in ATC (as a percent) | 60.00% | ||
| Equity investment in ATC | $ 1,422.5 | 1,380.9 | |
| Accounts payable due to ATC | $ 30.4 | $ 28.3 | |
| Purchased power agreement | |||
| Variable interest entities | |||
| Firm capacity from purchased power agreement (in megawatts) | MW | 236 | ||
| Minimum energy requirements over remaining term of purchased power agreement (in megawatts) | MW | 0 | ||
| Remaining term of purchased power agreement (in years) | 6 years | ||
| Residual guarantee associated with purchased power agreement | $ 0.0 | ||
| Required payments over remaining term of purchased power agreement | 119.2 | ||
| Total capacity and lease payments | 13.5 | $ 13.5 | |
| Accounting Standards Update 2015-02 | |||
| Variable interest entities | |||
| Changes to disclosures and financial statement presentation | $ 0.0 | ||
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- Definition Amount for accounts payable to related parties. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Under long-term contracts with public utility districts, cooperatives or other organizations, a utility company receives a portion of the output of a production plant constructed and financed by the district or cooperative. The utility has only a nominal or no investment at all in the plant but pays a proportionate part of the plant's costs, including debt service. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Represents the quantification of the effect of adopting the new accounting standard or change in accounting principle expected by the entity to have a significant effect on the entity's financial statements. 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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- Definition Firm capacity, in megawatts, from a purchased power agreement accounted for a capital lease. No definition available.
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- Definition The minimum energy requirements, in megawatts, over the remaining term of a purchased power agreement accounted for as a capital lease. No definition available.
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- Definition The remaining term, in years, of a purchased power agreement accounted for as a capital lease. No definition available.
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- Definition Amount of the residual guarantee associated with a purchased power agreement accounted for as a capital lease. No definition available.
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- Definition The total capacity and lease payments made under a purchased power agreement accounted for as a capital lease. No definition available.
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