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Pro Forma Summary (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
2018 acquisitions |  |  |
Pro Forma Information |  |  |
Net interest income and non-interest income | $ 560,979 | $ 520,634 |
Net income | $ 177,267 | 138,042 |
2017 acquisitions |  |  |
Pro Forma Information |  |  |
Net interest income and non-interest income |  | 462,603 | $ 436,678
Net income |  | $ 114,187 | $ 124,373

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