| **Supplemental Comprehensive Income Disclosures**            | 9 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
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| **Supplemental Comprehensive Income Disclosures [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| Supplemental Comprehensive Income Disclosures                | Supplemental Comprehensive Income DisclosuresThe following table identifies the related tax effects allocated to each component of other comprehensive income (“OCI”) in the Condensed Consolidated Statements of Comprehensive Income.  Reclassification adjustments related to securities available for sale are included in the "Net securities gains" line in the Condensed Consolidated Statements of Income.  The non-credit related gains on securities not expected to be sold are included in the "Noninterest Income" section of the Condensed Consolidated Statements of Income. For the Nine-Months Ended September 30 2013 2012 Pretax Amount Tax (Expense) Benefit Net of Tax Amount Pretax Amount Tax (Expense) Benefit Net of Tax Amount (dollars in thousands)Unrealized (losses) gains on securities:           Unrealized holding (losses) gains on securities arising during the period$(36,585) $12,799 $(23,786) $3,165 $(1,100) $2,065Non-credit related gains on securities not expected to be sold4,941 (1,729) 3,212 1,549 (542) 1,007Reclassification adjustment for gains on securities included in net income(237) 83 (154) (163) 57 (106)Total unrealized (losses) gains on securities(31,881) 11,153 (20,728) 4,551 (1,585) 2,966Total other comprehensive (loss) income$(31,881) $11,153 $(20,728) $4,551 $(1,585) $2,966             For the Three-Months Ended September 30 2013 2012 Pretax Amount Tax (Expense) Benefit Net of Tax Amount Pretax Amount Tax (Expense) Benefit Net of Tax Amount (dollars in thousands)Unrealized (losses) gains on securities:           Unrealized holding (losses) gains on securities arising during the period$(4,239) $1,487 $(2,752) $2,068 $(722) $1,346Non-credit related gains on securities not expected to be sold236 (82) 154 1,374 (481) 893Reclassification adjustment for gains on securities included in net income(229) 80 (149) (163) 57 (106)Total unrealized (losses) gains on securities(4,232) 1,485 (2,747) 3,279 (1,146) 2,133Total other comprehensive (loss) income$(4,232) $1,485 $(2,747) $3,279 $(1,146) $2,133 The following table details the change in components of OCI for the nine-months endedSeptember 30: 2013 2012 Securities Available for SalePost-Retirement ObligationAccumulated Other Comprehensive Income Securities Available for SalePost-Retirement ObligationAccumulated Other Comprehensive Income (dollars in thousands)Balance at December 31$1,121$138$1,259 $1,669$332$2,001Other comprehensive (loss) income before reclassification adjustment(23,786)—(23,786) 2,065—2,065Amounts reclassified from accumulated other comprehensive income (loss)3,058—3,058 901—901Net other comprehensive (loss) income during the period(20,728)—(20,728) 2,966—2,966Balance at September 30$(19,607)$138$(19,469) $4,635$332$4,967 |

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| - Definition
The entire disclosure for comprehensive income, which includes, but is not limited to, 1) the amount of income tax expense or benefit allocated to each component of other comprehensive income, including reclassification adjustments, 2) the reclassification adjustments for each classification of other comprehensive income and 3) the ending accumulated balances for each component of comprehensive income.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 14-26 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.  This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14 -URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e681-108580Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e637-108580Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187085-122770Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e689-108580Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=20435746&loc=SL7669619-108580Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e716-108580Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e640-108580Reference 9: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 16 -URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e709-108580Reference 10: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Reclassification Adjustments -URI http://asc.fasb.org/extlink&oid=6522872
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