| **Commitments and Contingent Liabilities (Tables)**     | 3 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                        |
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| **Commitments and Contingencies Disclosure [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| Notional Amount of Outstanding Commitments              | The following table identifies the notional amount of those instruments at: March 31, 2015 December 31, 2014 (dollars in thousands)Financial instruments whose contract amounts represent credit risk:   Commitments to extend credit$1,645,977 $1,635,948Financial standby letters of credit27,858 36,075Performance standby letters of credit26,490 25,915Commercial letters of credit2,584 2,611 |

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| - Definition
Tabular disclosure of short-term or long-term contractual arrangements with lenders, including letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(e),(f)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682
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