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Fair Value Accounting and Measurement (Carrying Amounts and Estimated Fair Values of Selected Financial Instruments) (Details) - USD ($) $ in Thousands | Sep. 30, 2017 | Dec. 31, 2016
--- | --- | ---
Assets |  |
Interest-earning deposits with banks | $ 136,578 | $ 31,200
Securities available for sale | 2,207,873 | 2,278,577
Carrying (Reported) Amount, Fair Value Disclosure [Member] |  |
Assets |  |
Cash and due from banks | 186,116 | 193,038
Interest-earning deposits with banks | 136,578 | 31,200
Securities available for sale | 2,207,873 | 2,278,577
FHLB stock | 10,240 | 10,240
Loans held for sale | 7,802 | 5,846
Loans | 6,440,390 | 6,143,380
FDIC loss-sharing asset |  | 3,535
Interest rate contracts | 8,992 | 9,012
Liabilities |  |
Deposits | 8,341,717 | 8,059,415
FHLB Advances | 6,465 | 6,493
Repurchase agreements | 40,933 | 80,822
Interest rate contracts | 9,004 | 9,036
Estimate of Fair Value, Fair Value Disclosure [Member] |  |
Assets |  |
Cash and due from banks | 186,116 | 193,038
Interest-earning deposits with banks | 136,578 | 31,200
Securities available for sale | 2,207,873 | 2,278,577
FHLB stock | 10,240 | 10,240
Loans held for sale | 7,802 | 5,846
Loans | 6,309,449 | 6,040,439
FDIC loss-sharing asset |  | 867
Interest rate contracts | 8,992 | 9,012
Liabilities |  |
Deposits | 8,337,145 | 8,055,168
FHLB Advances | 7,367 | 7,070
Repurchase agreements | 40,987 | 81,131
Interest rate contracts | 9,004 | 9,036
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] |  |
Assets |  |
Cash and due from banks | 186,116 | 193,038
Interest-earning deposits with banks | 136,578 | 31,200
Securities available for sale | 250 | 800
FHLB stock | 0 | 0
Loans held for sale | 0 | 0
Loans | 0 | 0
FDIC loss-sharing asset |  | 0
Interest rate contracts | 0 | 0
Liabilities |  |
Deposits | 7,960,870 | 7,653,122
FHLB Advances | 0 | 0
Repurchase agreements | 0 | 0
Interest rate contracts | 0 | 0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] |  |
Assets |  |
Cash and due from banks | 0 | 0
Interest-earning deposits with banks | 0 | 0
Securities available for sale | 2,207,623 | 2,277,777
FHLB stock | 10,240 | 10,240
Loans held for sale | 7,802 | 5,846
Loans | 0 | 0
FDIC loss-sharing asset |  | 0
Interest rate contracts | 8,992 | 9,012
Liabilities |  |
Deposits | 376,275 | 402,046
FHLB Advances | 7,367 | 7,070
Repurchase agreements | 40,987 | 81,131
Interest rate contracts | 9,004 | 9,036
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] |  |
Assets |  |
Cash and due from banks | 0 | 0
Interest-earning deposits with banks | 0 | 0
Securities available for sale | 0 | 0
FHLB stock | 0 | 0
Loans held for sale | 0 | 0
Loans | 6,309,449 | 6,040,439
FDIC loss-sharing asset |  | 867
Interest rate contracts | 0 | 0
Liabilities |  |
Deposits | 0 | 0
FHLB Advances | 0 | 0
Repurchase agreements | 0 | 0
Interest rate contracts | $ 0 | $ 0

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- Definition For banks and other depository institutions (including Federal Reserve Banks, if applicable): Interest-bearing deposits in other financial institutions for relatively short periods of time including, for example, certificates of deposits, which are presented separately from cash on the balance sheet. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.2) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=73530178&loc=d3e59706-112781 + Details
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