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Subsequent Event Subsequent Event (Details) (USD $) | 12 Months Ended |
--- | --- | ---
Dec. 31, 2013 | Dec. 31, 2012
Subsequent Event |  |
Subsequent Event, Date | Jan. 01, 2014 |
Subsequent Event, Description | Reclassify investment securities from available-for-sale to held-to-maturity |
Investment securities, available-for-sale | $ 3,222,829,000 | $ 3,683,005,000
Available-for-sale Securities, Gross Unrealized Gain Accumulated In Investments | 49,801,000 | 101,778,000
State and local governments |  |
Subsequent Event |  |
Investment securities, available-for-sale | 1,385,078,000 | 1,214,518,000
Available-for-sale Securities, Gross Unrealized Gain Accumulated In Investments | 31,621,000 | 88,095,000
Reclassification of AFS to HTM |  |
Subsequent Event |  |
Percent Available-For-Sale Prior to Reclassification | 100.00% |
Percent Available-For-Sale Subsequent to Reclassification | 85.00% |
Percent Held-To-Maturity Subsequent to Reclassification | 15.00% |
Reclassification of AFS to HTM | State and local governments |  |
Subsequent Event |  |
Investment securities, available-for-sale | 484,583,000 |
Available-for-sale Securities, Gross Unrealized Gain Accumulated In Investments | $ 4,624,000 |

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- Definition Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562 + Details
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