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Allowance for Probable Loan Losses (Portfolio Credit Quality By Loan Class) (Details) - USD ($) $ in Thousands | Mar. 31, 2017 | Dec. 31, 2016
--- | --- | ---
Loan portfolio by credit quality indicator |  |
Portfolio, total | $ 6,009,503 | $ 5,964,688
Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 5,607,839 | 5,544,614
Special Review |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 43,923 | 101,679
Watch List - Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 97,971 | 60,993
Watch List - Substandard |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 216,757 | 208,997
Watch - List Impaired |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 43,013 | 48,405
Commercial |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 864,193 | 909,667
Commercial | Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 688,694 | 720,350
Commercial | Special Review |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 35,310 | 90,746
Commercial | Watch List - Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 38,253 | 1,121
Commercial | Watch List - Substandard |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 80,600 | 75,038
Commercial | Watch - List Impaired |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 21,336 | 22,412
Commercial Real Estate: Other Construction and Land Development |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 1,778,282 | 1,716,875
Commercial Real Estate: Other Construction and Land Development | Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 1,711,225 | 1,648,633
Commercial Real Estate: Other Construction and Land Development | Special Review |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 923 | 1,986
Commercial Real Estate: Other Construction and Land Development | Watch List - Substandard |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 62,547 | 61,480
Commercial Real Estate: Other Construction and Land Development | Watch - List Impaired |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 3,587 | 4,776
Commercial Real Estate: Farmland & Commercial |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 1,957,672 | 1,943,070
Commercial Real Estate: Farmland & Commercial | Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 1,809,418 | 1,792,542
Commercial Real Estate: Farmland & Commercial | Special Review |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 7,496 | 7,983
Commercial Real Estate: Farmland & Commercial | Watch List - Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 59,718 | 59,872
Commercial Real Estate: Farmland & Commercial | Watch List - Substandard |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 73,043 | 71,863
Commercial Real Estate: Farmland & Commercial | Watch - List Impaired |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 7,997 | 10,810
Commercial Real Estate: Multifamily |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 145,098 | 140,466
Commercial Real Estate: Multifamily | Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 144,566 | 139,914
Commercial Real Estate: Multifamily | Watch - List Impaired |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 532 | 552
Residential First Lien |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 418,534 | 421,904
Residential First Lien | Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 411,333 | 413,638
Residential First Lien | Special Review |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 44 | 814
Residential First Lien | Watch List - Substandard |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 567 | 616
Residential First Lien | Watch - List Impaired |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 6,590 | 6,836
Residential Junior Lien |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 628,481 | 610,318
Residential Junior Lien | Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 627,363 | 609,190
Residential Junior Lien | Special Review |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 150 | 150
Residential Junior Lien | Watch - List Impaired |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 968 | 978
Consumer |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 53,614 | 55,168
Consumer | Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 52,368 | 53,873
Consumer | Watch - List Impaired |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 1,246 | 1,295
Foreign |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 163,629 | 167,220
Foreign | Pass |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | 162,872 | 166,474
Foreign | Watch - List Impaired |  |
Loan portfolio by credit quality indicator |  |
Portfolio, total | $ 757 | $ 746

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