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Loans Schedule of Loans by Class (Details) - USD ($) $ in Millions | Jun. 30, 2018 | Dec. 31, 2017
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Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Loans And Leases Receivable Held For Investment | $ 7,708.4 | $ 7,567.7
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group, Mortgage | 50.3 | 46.6
Loans and Leases Receivable, Gross | 7,758.7 | 7,614.3
Commercial |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Loans And Leases Receivable Held For Investment | 2,853.3 | 2,822.9
Land acquisition & development |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Loans And Leases Receivable Held For Investment | 355.6 | 348.7
Residential |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Loans And Leases Receivable Held For Investment | 227.8 | 240.2
Commercial Real Estate Construction [Member] |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Loans And Leases Receivable Held For Investment | 134.3 | 119.4
Total construction loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Loans And Leases Receivable Held For Investment | 717.7 | 708.3
Residential |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Loans And Leases Receivable Held For Investment | 1,486.2 | 1,487.4
Agricultural |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Loans And Leases Receivable Held For Investment | 175.7 | 158.2
Total real estate loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Loans And Leases Receivable Held For Investment | 5,232.9 | 5,176.8
Indirect consumer |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Loans And Leases Receivable Held For Investment | 795.4 | 784.7
Other consumer |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Loans And Leases Receivable Held For Investment | 182.5 | 175.1
Credit card |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Loans And Leases Receivable Held For Investment | 77.3 | 74.6
Total consumer loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Loans And Leases Receivable Held For Investment | 1,055.2 | 1,034.4
Commercial |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Loans And Leases Receivable Held For Investment | 1,266.0 | 1,215.4
Agricultural |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Loans And Leases Receivable Held For Investment | 151.2 | 136.2
Other, including overdrafts |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Loans And Leases Receivable Held For Investment | 3.1 | 4.9
Loans held for investment |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Loans And Leases Receivable Held For Investment | 7,708.4 | 7,567.7
Mortgage loans originated for sale |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group, Mortgage | 50.3 | 46.6
Total loans |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Loans and Leases Receivable, Gross | $ 7,758.7 | $ 7,614.3

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- Definition Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522 + Details
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