Supplemental Compensation Plans, Change in Benefit Obligation, Plan Assets, Funded Status and Amounts Recognized in Balance Sheets (Details) - Pension Plan [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Amounts recognized in the consolidated balance sheets consist of [Abstract]
Unrecognized net actuarial loss and prior service cost expected to be recognized in next fiscal year	$ 89
Salary Continuation Plan [Member]
Change in benefit obligation [Roll Forward]
Benefit obligation at beginning of year	5,419	$ 4,523	$ 4,261
Service cost	174	99	104
Interest cost	185	171	161
Plan loss (gain)	(184)	948	177
Benefits paid	(272)	(322)	(180)
Benefit obligation at end of year	5,322	5,419	4,523
Change in plan assets [Abstract]
Employer Contribution	272	322	180
Benefits paid	(272)	(322)	(180)
Fair value of plan assets at end of year	0	0	0
Reconciliation of funded status [Abstract]
Funded status	(5,322)	(5,419)	(4,523)
Unrecognized net plan loss (gain)	1,643	1,929	1,065
Unrecognized prior service cost	39	40	77
Net amount recognized	(3,640)	(3,450)	(3,381)
Amounts recognized in the consolidated balance sheets consist of [Abstract]
Accrued benefit liability	(5,322)	(5,419)	(4,523)
Accumulated other comprehensive loss	1,682	1,969	1,142
Net amount recognized	(3,640)	(3,450)	(3,381)
Directors' Retirement Plan [Member]
Change in benefit obligation [Roll Forward]
Benefit obligation at beginning of year	856	830	816
Service cost	12	11	11
Interest cost	25	27	27
Plan loss (gain)	(37)	18	6
Benefits paid	(69)	(30)	(30)
Benefit obligation at end of year	787	856	830
Change in plan assets [Abstract]
Employer Contribution	69	30	30
Benefits paid	(69)	(30)	(30)
Fair value of plan assets at end of year	0	0	0
Reconciliation of funded status [Abstract]
Funded status	(787)	(856)	(830)
Unrecognized net plan loss (gain)	(40)	(4)	(22)
Net amount recognized	(827)	(860)	(852)
Amounts recognized in the consolidated balance sheets consist of [Abstract]
Accrued benefit liability	(787)	(856)	(830)
Accumulated other comprehensive loss	(40)	(4)	(22)
Net amount recognized	$ (827)	$ (860)	$ (852)