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Parent Company Condensed Financial Information - Statements of Net Income (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Condensed Financial Information [Line Items] |  |  |
Interest expense on long-term debt | $ 670 | $ 790 | $ 617
Net Income | 71,392 | 67,081 | 57,910
Parent Company |  |  |
Condensed Financial Information [Line Items] |  |  |
Dividends from subsidiaries | 34,134 | 75,413 | 46,414
Investment income | 17 | 19 | 19
Interest expense on long-term debt | 854 | 773 | 759
Other expenses | 2,315 | 2,138 | 2,014
Income before Equity in Undistributed Net Income of Subsidiaries | 30,982 | 72,521 | 43,660
Bank subsidiary | 40,051 | (5,064) | 13,351
Nonbank subsidiaries | 359 | (376) | 899
Net Income | $ 71,392 | $ 67,081 | $ 57,910

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