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Bank Loans (Loans That Were Individually Evaluated For Impairment By Portfolio Segment) (Details) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2018 | Dec. 31, 2017
Financing Receivable Impaired [Line Items] |  |
Unpaid Contractual Principal Balance | $ 24,667 | $ 29,888
Recorded Investment with No Allowance |  | 5,211
Recorded Investment with Allowance | 23,994 | 24,002
Total Recorded Investment | 23,994 | 29,213
Related Allowance | 9,109 | 9,105
Average Recorded Investment | 23,958 | 30,756
Commercial And Industrial [Member] |  |
Financing Receivable Impaired [Line Items] |  |
Unpaid Contractual Principal Balance | 23,638 | 28,856
Recorded Investment with No Allowance |  | 5,211
Recorded Investment with Allowance | 23,638 | 23,645
Total Recorded Investment | 23,638 | 28,856
Related Allowance | 9,063 | 9,059
Average Recorded Investment | 23,601 | 30,277
Consumer [Member] |  |
Financing Receivable Impaired [Line Items] |  |
Unpaid Contractual Principal Balance | 675 | 677
Recorded Investment with Allowance | 2 | 2
Total Recorded Investment | 2 | 2
Related Allowance | 2 | 2
Average Recorded Investment | 2 | 5
Residential Real Estate [Member] |  |
Financing Receivable Impaired [Line Items] |  |
Unpaid Contractual Principal Balance | 170 | 171
Recorded Investment with Allowance | 170 | 171
Total Recorded Investment | 170 | 171
Related Allowance | 24 | 24
Average Recorded Investment | 171 | 174
Home Equity Lines Of Credit [Member] |  |
Financing Receivable Impaired [Line Items] |  |
Unpaid Contractual Principal Balance | 184 | 184
Recorded Investment with Allowance | 184 | 184
Total Recorded Investment | 184 | 184
Related Allowance | 20 | 20
Average Recorded Investment | $ 184 | $ 300

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- Definition Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5258-111524 + Details
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