Segment Reporting - Key Operating Results of Business Segments (Details) - USD ($) $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2017 |
Sep. 30, 2017 |
Jun. 30, 2017 |
Mar. 31, 2017 |
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, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Segment Reporting Information [Line Items] | |||||||||||||||
| Interest income | $ 37,911 | $ 34,878 | $ 33,652 | $ 30,360 | $ 28,367 | $ 26,004 | $ 24,573 | $ 21,698 | $ 19,212 | $ 17,108 | $ 14,993 | $ 13,158 | $ 136,801 | $ 100,642 | $ 64,471 |
| Interest expense | 6,686 | 6,438 | 5,757 | 4,302 | 3,363 | 2,841 | 2,652 | 2,337 | 1,778 | 1,647 | 1,569 | 1,287 | 23,183 | 11,193 | 6,281 |
| Net interest income | 31,225 | 28,440 | 27,895 | 26,058 | 25,004 | 23,163 | 21,921 | 19,361 | 17,434 | 15,461 | 13,424 | 11,871 | 113,618 | 89,449 | 58,190 |
| Provision for loan losses | 900 | 701 | 1,092 | 69 | 1,800 | 1,231 | 1,250 | 400 | 1,200 | 570 | 753 | 150 | 2,762 | 4,681 | 2,673 |
| Noninterest income | 11,376 | 9,863 | 9,697 | 7,783 | 7,586 | 15,079 | 4,910 | 6,985 | 9,281 | 6,868 | 6,420 | 6,204 | 38,719 | 34,560 | 28,773 |
| Noninterest expense | 28,661 | 23,393 | 22,213 | 24,709 | 20,191 | 21,536 | 19,850 | 19,417 | 17,170 | 16,956 | 13,974 | 13,358 | 98,976 | 80,994 | 61,458 |
| Income before taxes on income | $ 13,040 | $ 14,209 | $ 14,287 | $ 9,063 | $ 10,599 | $ 15,475 | $ 5,731 | $ 6,529 | $ 8,345 | $ 4,803 | $ 5,117 | $ 4,567 | 50,599 | 38,334 | 22,832 |
| Operating Segments | Banking | |||||||||||||||
| Segment Reporting Information [Line Items] | |||||||||||||||
| Interest income | 136,801 | 100,642 | 64,471 | ||||||||||||
| Interest expense | 22,530 | 11,193 | 5,607 | ||||||||||||
| Net interest income | 114,271 | 89,449 | 58,864 | ||||||||||||
| Provision for loan losses | 2,762 | 4,681 | 2,673 | ||||||||||||
| Noninterest income | 16,016 | 13,832 | 8,833 | ||||||||||||
| Noninterest expense | 73,990 | 58,422 | 39,982 | ||||||||||||
| Income before taxes on income | 53,535 | 40,178 | 25,042 | ||||||||||||
| Operating Segments | Wealth Management | |||||||||||||||
| Segment Reporting Information [Line Items] | |||||||||||||||
| Noninterest income | 23,556 | 21,348 | 20,530 | ||||||||||||
| Noninterest expense | 20,469 | 19,232 | 18,352 | ||||||||||||
| Income before taxes on income | 3,087 | 2,116 | 2,178 | ||||||||||||
| Other | |||||||||||||||
| Segment Reporting Information [Line Items] | |||||||||||||||
| Interest expense | 653 | 674 | |||||||||||||
| Net interest income | (653) | (674) | |||||||||||||
| Noninterest income | (853) | (620) | (590) | ||||||||||||
| Noninterest expense | 4,517 | 3,340 | 3,124 | ||||||||||||
| Income before taxes on income | $ (6,023) | $ (3,960) | $ (4,388) | ||||||||||||