Pension and Retirement Benefit Plans. (Details) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | |||
|---|---|---|---|---|---|
Sep. 30, 2021 |
Sep. 30, 2020 |
Sep. 30, 2021 |
Sep. 30, 2020 |
Dec. 31, 2020 |
|
| Retirement Plan [Member] | |||||
| Pension and Retirement Benefit Plans. (Details) [Line Items] | |||||
| Accumulated projected benefit obligation | $ 24,600 | ||||
| Fair value of plan assets | 17,600 | ||||
| Underfunded amount | 7,000 | ||||
| Net periodic expense | $ 22,000 | $ 48,000 | $ 66,000 | $ 144,000 | |
| Interest cost | 151,000 | 173,000 | 453,000 | 519,000 | |
| Service cost | 109,000 | 101,000 | 327,000 | 303,000 | |
| Expected return on plan assets | 238,000 | 226,000 | 714,000 | 678,000 | |
| Post Retirement Plan [Member] | |||||
| Pension and Retirement Benefit Plans. (Details) [Line Items] | |||||
| Accumulated projected benefit obligation | $ 5,300 | ||||
| Net periodic expense | 42,000 | 59,000 | 126,000 | 177,000 | |
| Interest cost | 10,000 | 38,000 | 30,000 | 114,000 | |
| Service cost | 26,000 | 14,000 | 78,000 | 42,000 | |
| Amortization expense | $ 6,000 | $ 7,000 | $ 18,000 | $ 21,000 | |
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Amount of actuarial present value of benefits attributed to employee service rendered, excluding assumptions about future compensation level. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Amount of funded (unfunded) status of defined benefit plan, measured as difference between fair value of plan assets and benefit obligation. Includes, but is not limited to, overfunded (underfunded) status. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of cost recognized for passage of time related to defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of net periodic benefit cost (credit) for defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of plan asset for defined benefit plan with accumulated benefit obligation in excess of plan assets. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|