Supplemental Retirement Plan and Related Post Retirement Benefits - Summary of the Components of Net Periodic Cost (Details) $ in Thousands |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
|
Sep. 30, 2017
USD ($)
|
Oct. 01, 2016
USD ($)
|
Sep. 30, 2017
USD ($)
retirement_plan
|
Oct. 01, 2016
USD ($)
|
|
| Retirement Benefits [Abstract] | ||||
| Number of non-qualified supplemental retirement defined benefit plans | retirement_plan | 2 | |||
| SERP | ||||
| Defined Benefit Plan Disclosure | ||||
| Service Cost | $ 46 | $ 43 | $ 138 | $ 130 |
| Interest Cost | 224 | 225 | 672 | 675 |
| Amortization of Prior Service Cost | 97 | 103 | 291 | 310 |
| Amortization of Net Actuarial Losses | 93 | 86 | 279 | 257 |
| Net Periodic Cost | 460 | 457 | 1,380 | 1,372 |
| SERP | SERP Medical | ||||
| Defined Benefit Plan Disclosure | ||||
| Service Cost | 2 | 1 | 6 | 4 |
| Interest Cost | 10 | 10 | 30 | 30 |
| Amortization of Prior Service Cost | 4 | 7 | 12 | 19 |
| Amortization of Net Actuarial Losses | 7 | 4 | 21 | 16 |
| Net Periodic Cost | $ 23 | $ 22 | $ 69 | $ 69 |
| X | ||||||||||
- Definition Number of non-qualified supplemental retirement defined benefit plans. No definition available.
|
| X | ||||||||||
- References No definition available.
|
| 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/presentationRef
|
| X | ||||||||||
- Definition Amount of prior service cost (credit) recognized in net periodic benefit cost (credit) of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
|
| X | ||||||||||
- Definition Amount of cost recognized for passage of time related to defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of net periodic benefit cost (credit) for defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| 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/presentationRef
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|