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Fair Value Of Assets And Liabilities (Narrative) (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2018 | Dec. 31, 2017 | Sep. 30, 2017 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017
Segment Reporting Information [Line Items] |  |  |  |  |  |
Gain/(loss) on instrument specific credit risk | $ 0.0 |  |  | $ 0.2 | $ 0.3 | $ 0.3
Corporate Segment |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |
Long-lived asset impairment | $ 1.3 | $ 3.0 | $ 2.0 |  |  |
Regional Banking |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |
Long-lived asset impairment |  | $ 0.8 |  |  |  |

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- Definition Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=68055307&loc=d3e2420-110228 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585 + Details
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- Definition This item represents the estimated amount of gains or losses included in earnings during the period attributable to changes in instrument-specific credit risk arising from loans and other receivables held as assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 30 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=75031198&loc=d3e14172-108612 + Details
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