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Assets and Liabilities Held for Sale Pretax Income (Tables) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
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Sep. 30, 2020 | Sep. 30, 2019 | Sep. 30, 2020 | Sep. 30, 2019
Massachusetts Business |  |  |  |
Assets and Liabilities Held for Sale Pretax Income [Line Items] |  |  |  |
Disposal Group, Including Discontinued Operation, Operating Income (Loss) | $ (74.1) | $ (55.2) | $ (402.9) | $ 183.5

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- Definition Assets and Liabilities Held for Sale Pretax Income + References No definition available. + Details
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- Definition Amount of operating income (loss) attributable to disposal group, including, but not limited to, discontinued operation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 5B -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721673-107760 + Details
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- Details
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