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Mergers and Acquisitions Pro Forma Summary (Details) - 2015 acquisitions - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
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Jun. 30, 2015 | Jun. 30, 2014 | Jun. 30, 2015 | Jun. 30, 2014
Pro Forma Information |  |  |  |
Net interest income and non-interest income | $ 97,050 | $ 91,956 | $ 191,004 | $ 180,734
Net income | $ 29,335 | $ 28,882 | $ 57,006 | $ 55,798

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