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Segments - Financial Information of Segments (Detail) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2016 | Sep. 30, 2015 | Sep. 30, 2016 | Sep. 30, 2015
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |
Interest income | $ 57,808 | $ 53,669 | $ 168,678 | $ 150,195
Interest expense | 6,353 | 4,073 | 17,877 | 11,529
NET INTEREST INCOME | 51,455 | 49,596 | 150,801 | 138,666
Provision for loan losses | 2,516 | 3,206 | 12,379 | 6,473
Noninterest income | 13,448 | 12,481 | 41,713 | 37,948
Noninterest expense | 32,780 | 32,138 | 102,641 | 98,014
Depreciation expense | 1,284 | 1,211 | 3,723 | 3,540
Amortization of intangible assets | 375 | 480 | 1,243 | 1,345
Provision for income taxes | 7,367 | 6,407 | 18,795 | 17,584
Net Income | 20,581 | 18,635 | 53,733 | 49,658
Operating Segments | Community Banking |  |  |  |
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |
Interest income | 57,804 | 53,625 | 168,661 | 150,108
Interest expense | 6,433 | 4,200 | 18,085 | 12,144
NET INTEREST INCOME | 51,371 | 49,425 | 150,576 | 137,964
Provision for loan losses | 2,516 | 3,206 | 12,379 | 6,473
Noninterest income | 9,548 | 8,651 | 28,468 | 25,056
Noninterest expense | 28,889 | 28,941 | 90,499 | 87,542
Depreciation expense | 1,269 | 1,192 | 3,678 | 3,482
Amortization of intangible assets | 359 | 460 | 1,189 | 1,283
Provision for income taxes | 7,347 | 6,139 | 18,364 | 16,534
Net Income | 20,539 | 18,138 | 52,935 | 47,706
Operating Segments | Insurance |  |  |  |
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |
Interest income | 1 | 1 | 2 | 2
NET INTEREST INCOME | 1 | 1 | 2 | 2
Noninterest income | 1,119 | 1,197 | 3,836 | 4,079
Noninterest expense | 1,097 | 1,098 | 3,455 | 3,288
Depreciation expense | 11 | 13 | 33 | 39
Amortization of intangible assets | 12 | 13 | 37 | 38
Provision for income taxes | (1) | 26 | 110 | 250
Net Income | 1 | 48 | 203 | 466
Operating Segments | Wealth Management |  |  |  |
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |
Interest income | 98 | 108 | 343 | 406
NET INTEREST INCOME | 98 | 108 | 343 | 406
Noninterest income | 2,563 | 2,806 | 7,936 | 8,639
Noninterest expense | 2,591 | 2,210 | 7,334 | 6,716
Depreciation expense | 4 | 6 | 12 | 19
Amortization of intangible assets | 4 | 7 | 17 | 24
Provision for income taxes | 21 | 242 | 321 | 800
Net Income | 41 | 449 | 595 | 1,486
Eliminations |  |  |  |
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |
Interest income | (95) | (65) | (328) | (321)
Interest expense | (80) | (127) | (208) | (615)
NET INTEREST INCOME | (15) | 62 | (120) | 294
Noninterest income | 218 | (173) | 1,473 | 174
Noninterest expense | $ 203 | $ (111) | $ 1,353 | $ 468

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