PENSION PLANS. (Tables)
   | 
9 Months Ended | 
12 Months Ended | 
Sep. 30, 2019  | 
Dec. 31, 2018  | 
| Schedule of defined contribution plan schedule | 
    |   | 
  | 
    Three Months Ended  September 30, | 
  | 
  | 
    Nine Months Ended  September 30, | 
  | 
 
    |   | 
  | 
    2019 | 
  | 
  | 
    2018 | 
  | 
  | 
    2019 | 
  | 
  | 
    2018 | 
  | 
 
    |   | 
  | 
      | 
  | 
  | 
      | 
  | 
  | 
      | 
  | 
  | 
      | 
  | 
 
    | Interest cost | 
  | 
    $ | 
55 | 
  | 
  | 
    $ | 
46 | 
  | 
  | 
    $ | 
165 | 
  | 
  | 
    $ | 
138 | 
  | 
 
    | Service cost | 
  | 
      | 
17 | 
  | 
  | 
      | 
2 | 
  | 
  | 
      | 
51 | 
  | 
  | 
      | 
6 | 
  | 
 
    | Amortization of loss | 
  | 
      | 
30 | 
  | 
  | 
      | 
33 | 
  | 
  | 
      | 
90 | 
  | 
  | 
      | 
99 | 
  | 
 
    | Net periodic expense | 
  | 
    $ | 
102 | 
  | 
  | 
    $ | 
81 | 
  | 
  | 
    $ | 
306 | 
  | 
  | 
    $ | 
243 | 
  | 
 
 
 | 
 
 | 
| Schedule of retirement plan costs | 
    |   | 
  | 
    Three Months Ended  September 30, | 
  | 
  | 
    Nine Months Ended  September 30, | 
  | 
 
    |   | 
  | 
    2019 | 
  | 
  | 
    2018 | 
  | 
  | 
    2019 | 
  | 
  | 
    2018 | 
  | 
 
    |   | 
  | 
      | 
  | 
  | 
      | 
  | 
  | 
      | 
  | 
  | 
      | 
  | 
 
    | Interest cost | 
  | 
    $ | 
190 | 
  | 
  | 
    $ | 
174 | 
  | 
  | 
    $ | 
570 | 
  | 
  | 
    $ | 
522 | 
  | 
 
    | Service cost | 
  | 
      | 
94 | 
  | 
  | 
      | 
106 | 
  | 
  | 
      | 
282 | 
  | 
  | 
      | 
318 | 
  | 
 
    | Expected return on plan assets | 
  | 
      | 
(190 | 
) | 
  | 
      | 
(204 | 
) | 
  | 
      | 
(570 | 
) | 
  | 
      | 
(612 | 
) | 
 
    | Net periodic expense | 
  | 
    $ | 
94 | 
  | 
  | 
    $ | 
76 | 
  | 
  | 
    $ | 
282 | 
  | 
  | 
    $ | 
228 | 
  | 
 
 
 | 
 
 | 
| Postretirement Plan [Member] | 
 
 | 
 
 | 
| Schedule of defined contribution plan schedule | 
 
 | 
 Information
related to the Retirement Plan as of and for the years ended December 31, 2018, 2017 and 2016 is presented below (dollars in thousands):  
  
    |   | 
      | 
    2018 | 
      | 
      | 
    2017 | 
      | 
      | 
    2016 | 
      | 
 
    |   | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Changes
    in plan assets: | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Fair
    value of plan assets, beginning | 
      | 
    $ | 
    13,958 | 
      | 
      | 
    $ | 
    12,423 | 
      | 
      | 
    $ | 
    12,567 | 
      | 
 
    | Actual
    gains (losses) | 
      | 
      | 
    (946 | 
    ) | 
      | 
      | 
    1,722 | 
      | 
      | 
      | 
    523 | 
      | 
 
    | Benefits
    paid | 
      | 
      | 
    (667 | 
    ) | 
      | 
      | 
    (665 | 
    ) | 
      | 
      | 
    (667 | 
    ) | 
 
    | Company
    contributions | 
      | 
      | 
    912 | 
      | 
      | 
      | 
    478 | 
      | 
      | 
      | 
    — | 
      | 
 
    | Participant
    contributions | 
      | 
      | 
    — | 
      | 
      | 
      | 
    — | 
      | 
      | 
      | 
    — | 
      | 
 
    | Fair
    value of plan assets, ending | 
      | 
    $ | 
    13,257 | 
      | 
      | 
    $ | 
    13,958 | 
      | 
      | 
    $ | 
    12,423 | 
      | 
 
    | Less:
    projected accumulated benefit obligation | 
      | 
    $ | 
    18,690 | 
      | 
      | 
    $ | 
    19,658 | 
      | 
      | 
    $ | 
    18,455 | 
      | 
 
    | Funded
    status, (underfunded)/overfunded | 
      | 
    $ | 
    (5,433 | 
    ) | 
      | 
    $ | 
    (5,700 | 
    ) | 
      | 
    $ | 
    (6,032 | 
    ) | 
 
    |   | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Amounts
    recognized in the consolidated balance sheets: | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Other
    liabilities | 
      | 
    $ | 
    (5,433 | 
    ) | 
      | 
    $ | 
    (5,700 | 
    ) | 
      | 
    $ | 
    (6,032 | 
    ) | 
 
    | Accumulated
    other comprehensive loss (income) | 
      | 
    $ | 
    1,069 | 
      | 
      | 
    $ | 
    726 | 
      | 
      | 
    $ | 
    1,047 | 
      | 
 
    |   | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Components
    of net periodic benefit costs are as follows: | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Service
    cost | 
      | 
    $ | 
    424 | 
      | 
      | 
    $ | 
    391 | 
      | 
      | 
    $ | 
    223 | 
      | 
 
    | Interest
    cost | 
      | 
      | 
    694 | 
      | 
      | 
      | 
    750 | 
      | 
      | 
      | 
    686 | 
      | 
 
    | Expected
    return on plan assets | 
      | 
      | 
    (816 | 
    ) | 
      | 
      | 
    (674 | 
    ) | 
      | 
      | 
    (794 | 
    ) | 
 
    | Net
    periodic benefit cost | 
      | 
    $ | 
    302 | 
      | 
      | 
    $ | 
    467 | 
      | 
      | 
    $ | 
    115 | 
      | 
 
    | Loss
    (gain) recognized in other comprehensive income (expense) | 
      | 
    $ | 
    343 | 
      | 
      | 
    $ | 
    (321 | 
    ) | 
      | 
    $ | 
    1,932 | 
      | 
 
    |   | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Assumptions
    used in computation benefit obligations: | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Discount
    rate | 
      | 
      | 
    4.15 | 
    % | 
      | 
      | 
    3.60 | 
    % | 
      | 
      | 
    4.15 | 
    % | 
 
    | Expected
    long-term return on plan assets | 
      | 
      | 
    6.25 | 
    % | 
      | 
      | 
    6.00 | 
    % | 
      | 
      | 
    6.75 | 
    % | 
 
    | Rate
    of compensation increase | 
      | 
      | 
    — | 
      | 
      | 
      | 
    — | 
      | 
      | 
      | 
    — | 
 
 
 | 
| Schedule of expected benefit payments | 
 
 | 
 The
following table summarizes the expected benefit payments for the Company's Retirement Plan for each of the next five fiscal
years and in the aggregate for the five fiscal years thereafter (in thousands): 
  
    | December 31: | 
  | 
      | 
  | 
 
    | 2019 | 
  | 
    $ | 
760 | 
  | 
 
    | 2020 | 
  | 
      | 
790 | 
  | 
 
    | 2021 | 
  | 
      | 
800 | 
  | 
 
    | 2022 | 
  | 
      | 
840 | 
  | 
 
    | 2023 | 
  | 
      | 
890 | 
  | 
 
    | 2024-28 | 
  | 
      | 
5,100 | 
  | 
 
    |   | 
  | 
    $ | 
9,180 | 
  | 
 
 
 | 
| Retirement Plan [Member] | 
 
 | 
 
 | 
| Schedule of defined contribution plan schedule | 
 
 | 
 Information
related to the Postretirement Plan as of December 31, 2018 and 2017 is presented below (dollars in thousands): 
  
    |   | 
      | 
    2018 | 
      | 
      | 
    2017 | 
      | 
 
    |   | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Amounts
    at the end of the year: | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Accumulated/projected
    benefit obligation | 
      | 
    $ | 
    5,711 | 
      | 
      | 
    $ | 
    5,565 | 
      | 
 
    | Fair
    value of plan assets | 
      | 
      | 
    — | 
      | 
      | 
      | 
      | 
      | 
 
    | Funded
    status, (underfunded)/overfunded | 
      | 
    $ | 
    (5,711 | 
    ) | 
      | 
    $ | 
    (5,565 | 
    ) | 
 
    |   | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Amounts
    recognized in the consolidated balance sheets: | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Accrued
    liabilities | 
      | 
    $ | 
    (320 | 
    ) | 
      | 
    $ | 
    (240 | 
    ) | 
 
    | Other
    liabilities | 
      | 
    $ | 
    (5,392 | 
    ) | 
      | 
    $ | 
    (5,325 | 
    ) | 
 
    | Accumulated
    other comprehensive loss | 
      | 
    $ | 
    1,390 | 
      | 
      | 
    $ | 
    1,508 | 
      | 
 
 
  
    |   | 
      | 
    Years
    Ended December 31, | 
      | 
 
    |   | 
      | 
    2018 | 
      | 
      | 
    2017 | 
      | 
      | 
    2016 | 
      | 
 
    |   | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Amounts
    recognized in the plan for the year: | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Company
    contributions | 
      | 
    $ | 
    137 | 
      | 
      | 
    $ | 
    157 | 
      | 
      | 
    $ | 
    163 | 
      | 
 
    | Participant
    contributions | 
      | 
    $ | 
    14 | 
      | 
      | 
    $ | 
    22 | 
      | 
      | 
    $ | 
    22 | 
      | 
 
    | Benefits
    paid | 
      | 
    $ | 
    (152 | 
    ) | 
      | 
    $ | 
    (179 | 
    ) | 
      | 
    $ | 
    (184 | 
    ) | 
 
    |   | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Components
    of net periodic benefit costs are as follows: | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Service
    cost | 
      | 
    $ | 
    84 | 
      | 
      | 
    $ | 
    84 | 
      | 
      | 
    $ | 
    48 | 
      | 
 
    | Interest
    cost | 
      | 
      | 
    182 | 
      | 
      | 
      | 
    198 | 
      | 
      | 
      | 
    139 | 
      | 
 
    | Amortization
    of prior service costs | 
      | 
      | 
    131 | 
      | 
      | 
      | 
    134 | 
      | 
      | 
      | 
    — | 
      | 
 
    | Net
    periodic benefit cost | 
      | 
    $ | 
    397 | 
      | 
      | 
    $ | 
    416 | 
      | 
      | 
    $ | 
    187 | 
      | 
 
    |   | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Loss
    (gain) recognized in other comprehensive income | 
      | 
    $ | 
    (118 | 
    ) | 
      | 
    $ | 
    (65 | 
    ) | 
      | 
    $ | 
    1,728 | 
      | 
 
    |   | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Discount
    rate used in computation of benefit obligations | 
      | 
      | 
    3.35 | 
    % | 
      | 
      | 
    3.80 | 
    % | 
      | 
      | 
    3.95 | 
    % | 
 
 
 | 
| Schedule of expected benefit payments | 
 
 | 
 The
following table summarizes the expected benefit payments for the Company's Post-Retirement Plan for each of the next five
fiscal years and in the aggregate for the five fiscal years thereafter (in thousands): 
  
    | December 31: | 
  | 
      | 
  | 
 
    | 2019 | 
  | 
    $ | 
320 | 
  | 
 
    | 2020 | 
  | 
      | 
320 | 
  | 
 
    | 2021 | 
  | 
      | 
370 | 
  | 
 
    | 2022 | 
  | 
      | 
360 | 
  | 
 
    | 2023 | 
  | 
      | 
390 | 
  | 
 
    | 2024-28 | 
  | 
      | 
2,350 | 
  | 
 
    |   | 
  | 
    $ | 
4,110 | 
  | 
 
 
 |