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Segments - Financial Information of Segments (Details) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2016 | Sep. 30, 2016 | Jun. 30, 2016 | Mar. 31, 2016 | Dec. 31, 2015 | Sep. 30, 2015 | Jun. 30, 2015 | Mar. 31, 2015 | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |  |  |  |  |  |  |  |
Interest income | $ 59,096 | $ 57,808 | $ 55,850 | $ 55,019 | $ 53,353 | $ 53,669 | $ 52,611 | $ 43,916 | $ 227,774 | $ 203,548 | $ 160,523
Interest expense | 6,638 | 6,353 | 6,142 | 5,382 | 4,468 | 4,073 | 3,800 | 3,657 | 24,515 | 15,997 | 12,481
NET INTEREST INCOME |  |  |  |  |  |  |  |  | 203,259 | 187,551 | 148,042
Provision for loan losses | 5,586 | 2,516 | 4,848 | 5,014 | 3,915 | 3,206 | 2,059 | 1,207 | 17,965 | 10,388 | 1,715
Noninterest income | 12,922 | 13,448 | 12,448 | 15,817 | 13,084 | 12,481 | 13,417 | 12,084 | 54,635 | 51,033 | 46,338
Noninterest expense |  |  |  |  |  |  |  |  | 136,651 | 130,160 | 112,646
Depreciation expense |  |  |  |  |  |  |  |  | 4,966 | 4,739 | 3,465
Amortization of intangible assets |  |  |  |  |  |  |  |  | 1,615 | 1,818 | 1,129
Provision (benefit) for income taxes | $ 6,510 | $ 7,367 | $ 5,496 | $ 5,931 | $ 6,814 | $ 6,407 | $ 6,498 | $ 4,680 | 25,305 | 24,398 | 17,515
Net Income |  |  |  |  |  |  |  |  | 71,392 | 67,081 | 57,910
Operating Segments | Community Banking |  |  |  |  |  |  |  |  |  |  |
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |  |  |  |  |  |  |  |
Interest income |  |  |  |  |  |  |  |  | 227,756 | 203,439 | 160,403
Interest expense |  |  |  |  |  |  |  |  | 24,851 | 16,678 | 13,989
NET INTEREST INCOME |  |  |  |  |  |  |  |  | 202,905 | 186,761 | 146,414
Provision for loan losses |  |  |  |  |  |  |  |  | 17,965 | 10,388 | 1,715
Noninterest income |  |  |  |  |  |  |  |  | 37,717 | 34,106 | 29,443
Noninterest expense |  |  |  |  |  |  |  |  | 120,744 | 115,998 | 97,733
Depreciation expense |  |  |  |  |  |  |  |  | 4,905 | 4,664 | 3,387
Amortization of intangible assets |  |  |  |  |  |  |  |  | 1,543 | 1,738 | 1,039
Provision (benefit) for income taxes |  |  |  |  |  |  |  |  | 24,872 | 23,209 | 16,311
Net Income |  |  |  |  |  |  |  |  | 70,593 | 64,870 | 55,672
Operating Segments | Insurance |  |  |  |  |  |  |  |  |  |  |
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |  |  |  |  |  |  |  |
Interest income |  |  |  |  |  |  |  |  | 2 | 2 | 2
Interest expense |  |  |  |  |  |  |  |  | 0 | 0 | 0
NET INTEREST INCOME |  |  |  |  |  |  |  |  | 2 | 2 | 2
Provision for loan losses |  |  |  |  |  |  |  |  | 0 | 0 | 0
Noninterest income |  |  |  |  |  |  |  |  | 4,794 | 5,035 | 5,279
Noninterest expense |  |  |  |  |  |  |  |  | 4,582 | 4,365 | 4,313
Depreciation expense |  |  |  |  |  |  |  |  | 45 | 50 | 51
Amortization of intangible assets |  |  |  |  |  |  |  |  | 50 | 50 | 51
Provision (benefit) for income taxes |  |  |  |  |  |  |  |  | 42 | 200 | 303
Net Income |  |  |  |  |  |  |  |  | 77 | 372 | 563
Operating Segments | Wealth Management |  |  |  |  |  |  |  |  |  |  |
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |  |  |  |  |  |  |  |
Interest income |  |  |  |  |  |  |  |  | 459 | 508 | 518
Interest expense |  |  |  |  |  |  |  |  | 0 | 0 | 0
NET INTEREST INCOME |  |  |  |  |  |  |  |  | 459 | 508 | 518
Provision for loan losses |  |  |  |  |  |  |  |  | 0 | 0 | 0
Noninterest income |  |  |  |  |  |  |  |  | 10,443 | 11,412 | 11,297
Noninterest expense |  |  |  |  |  |  |  |  | 9,751 | 9,037 | 9,173
Depreciation expense |  |  |  |  |  |  |  |  | 16 | 25 | 27
Amortization of intangible assets |  |  |  |  |  |  |  |  | 22 | 30 | 39
Provision (benefit) for income taxes |  |  |  |  |  |  |  |  | 391 | 989 | 901
Net Income |  |  |  |  |  |  |  |  | 722 | 1,839 | 1,675
Eliminations |  |  |  |  |  |  |  |  |  |  |
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |  |  |  |  |  |  |  |
Interest income |  |  |  |  |  |  |  |  | (443) | (401) | (400)
Interest expense |  |  |  |  |  |  |  |  | (336) | (681) | (1,508)
NET INTEREST INCOME |  |  |  |  |  |  |  |  | (107) | 280 | 1,108
Provision for loan losses |  |  |  |  |  |  |  |  | 0 | 0 | 0
Noninterest income |  |  |  |  |  |  |  |  | 1,681 | 480 | 319
Noninterest expense |  |  |  |  |  |  |  |  | 1,574 | 760 | 1,427
Depreciation expense |  |  |  |  |  |  |  |  | 0 | 0 | 0
Amortization of intangible assets |  |  |  |  |  |  |  |  | 0 | 0 | 0
Provision (benefit) for income taxes |  |  |  |  |  |  |  |  | 0 | 0 | 0
Net Income |  |  |  |  |  |  |  |  | $ 0 | $ 0 | $ 0

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