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Allowance for Probable Loan Losses (Portfolio Credit Quality By Loan Class) (Details) - USD ($) $ in Thousands | Jun. 30, 2019 | Dec. 31, 2018
--- | --- | ---
Loan portfolio by credit quality indicator |  |
Portfolio, total | $ 6,842,701 | $ 6,561,289
Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 6,508,353 | 6,126,933
Special Review |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 56,177 | 64,135
Watch List - Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 46,397 | 92,976
Watch List - Substandard |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 208,067 | 253,345
Watch - List Impaired |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 23,707 | 23,900
Commercial |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 1,202,743 | 1,128,969
Commercial | Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 1,141,456 | 998,625
Commercial | Special Review |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 19 | 441
Commercial | Watch List - Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 1,694 | 44,544
Commercial | Watch List - Substandard |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 51,101 | 76,180
Commercial | Watch - List Impaired |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 8,473 | 9,179
Commercial Real Estate:Other Construction and Land Development |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 2,010,198 | 1,886,231
Commercial Real Estate:Other Construction and Land Development | Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 1,942,982 | 1,817,098
Commercial Real Estate:Other Construction and Land Development | Special Review |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total |  | 1,648
Commercial Real Estate:Other Construction and Land Development | Watch List - Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 9,310 | 9,055
Commercial Real Estate:Other Construction and Land Development | Watch List - Substandard |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 55,982 | 56,338
Commercial Real Estate:Other Construction and Land Development | Watch - List Impaired |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 1,924 | 2,092
Commercial Real Estate: Farmland and Commercial |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 2,027,996 | 1,949,898
Commercial Real Estate: Farmland and Commercial | Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 1,834,448 | 1,726,711
Commercial Real Estate: Farmland and Commercial | Special Review |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 56,158 | 62,046
Commercial Real Estate: Farmland and Commercial | Watch List - Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 34,394 | 38,373
Commercial Real Estate: Farmland and Commercial | Watch List - Substandard |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 98,836 | 119,259
Commercial Real Estate: Farmland and Commercial | Watch - List Impaired |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 4,160 | 3,509
Commercial Real Estate: Multifamily |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 221,431 | 226,257
Commercial Real Estate: Multifamily | Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 220,023 | 224,823
Commercial Real Estate: Multifamily | Watch List - Substandard |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 903 | 927
Commercial Real Estate: Multifamily | Watch - List Impaired |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 505 | 507
Residential First Lien |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 460,178 | 445,800
Residential First Lien | Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 452,493 | 438,773
Residential First Lien | Watch List - Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 143 | 142
Residential First Lien | Watch List - Substandard |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 1,245 | 641
Residential First Lien | Watch - List Impaired |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 6,297 | 6,244
Residential Junior Lien |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 725,264 | 727,301
Residential Junior Lien | Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 723,385 | 725,538
Residential Junior Lien | Watch List - Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 856 | 862
Residential Junior Lien | Watch - List Impaired |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 1,023 | 901
Consumer |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 46,713 | 46,316
Consumer | Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 45,667 | 45,141
Consumer | Watch - List Impaired |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 1,046 | 1,175
Foreign |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 148,178 | 150,517
Foreign | Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 147,899 | 150,224
Foreign | Watch - List Impaired |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | $ 279 | $ 293

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