Employee Benefit Plans (Components of the Net Periodic Pension Plan Cost) (SERP) (Details) - SERP [Member] - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2017 |
Sep. 30, 2016 |
Sep. 30, 2017 |
Sep. 30, 2016 |
|
| Defined Benefit Plan Disclosure [Line Items] | ||||
| Service cost | $ 26 | $ 24 | $ 78 | $ 73 |
| Interest cost | 72 | 62 | 216 | 187 |
| Amortization of recognized (gain)/ loss | 37 | 20 | 110 | 59 |
| Amortization of prior service cost | (1) | 5 | (2) | 15 |
| Net pension expense/(credit) included in employee benefits | $ 134 | $ 111 | $ 402 | $ 334 |