Retirement Plans and Related Post Retirement Benefits - Reconciliation of Beginning and Ending Balances of Projected Benefit Obligation (Detail) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| SERP | |||
| Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | |||
| Balance at beginning of the year | $ 20,418 | $ 20,990 | |
| Service Cost | 173 | 194 | $ 247 |
| Interest Cost | 901 | 843 | 721 |
| Actuarial (Gain) Loss | 389 | (1,261) | |
| Benefits Paid | (348) | (348) | |
| Balance at end of the year | 21,533 | 20,418 | 20,990 |
| SERP Medical | |||
| Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | |||
| Balance at beginning of the year | 925 | 990 | |
| Service Cost | 5 | 6 | 3 |
| Interest Cost | 40 | 39 | 31 |
| Actuarial (Gain) Loss | 112 | (54) | |
| Benefits Paid | (61) | (56) | |
| Balance at end of the year | $ 1,021 | $ 925 | $ 990 |
| X | ||||||||||
- Definition Amount of gain (loss) related to change in benefit obligation resulting from changes in actuarial assumptions, for example, but not limited to, interest, mortality, employee turnover, salary, and temporary deviation from the substantive plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition 1) For defined benefit pension plans, the benefit obligation is the projected benefit obligation, which is the actuarial present value as of a date of all benefits attributed by the pension benefit formula to employee service rendered prior to that date. 2) For other postretirement defined benefit plans, the benefit obligation is the accumulated postretirement benefit obligation, which is the actuarial present value of benefits attributed to employee service rendered to a particular date. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The amount of payments made for which participants are entitled under a pension plan, including pension benefits, death benefits, and benefits due on termination of employment. Also includes payments made under a postretirement benefit plan, including prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services. This item represents a periodic decrease to the plan obligations and a decrease to plan assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The increase in a defined benefit pension plan's projected benefit obligation or a defined benefit postretirement plan's accumulated postretirement benefit obligation due to the passage of time. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The actuarial present value of benefits attributed by the pension benefit formula to services rendered by employees during the period. The portion of the expected postretirement benefit obligation attributed to employee service during the period. The service cost component is a portion of the benefit obligation and is unaffected by the funded status of the 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 | ||||||||||
- Details
|
| X | ||||||||||
- Details
|