SERP Benefits Table (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Change in plan assets
Fair value of plan assets at beginning of year	$ 16,200
Fair value of plan assets at end of year	16,600	$ 16,200
Supplemental Executive Retirement Plans [Member]
Change in accumulated benefit obligation
Benefit obligation at beginning of year	15,749	14,177	$ 13,290
Service cost	459	423	395
Interest cost	533	547	539
Actuarial loss (gain)	(1,344)	969	273
Accumulated benefit obligation at end of year	14,963	15,749	14,177
Defined Benefit Plan, Benefit Obligation, Benefits Paid	(434)	(367)	(320)
Change in plan assets
Employer contribution	434	367	320
Defined Benefit Plan, Plan Assets, Benefits Paid	(434)	(367)	(320)
Funded status at end of year	(14,963)	(15,749)	(14,177)
Assets	0	0	0
Liabilities	(14,963)	(15,749)	(14,177)
Funded status at end of year	(14,963)	(15,749)	(14,177)
Amounts recognized in accumulated other comprehensive income (“AOCI”)
Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax	1,705	3,465	2,830
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, Prior Service Cost (Credit), before Tax	770	1,047	1,323
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax	2,475	4,512	4,153
Information for plans with an accumulated benefit obligation in excess of plan assets
Projected benefit obligation	14,963	15,749	14,177
Accumulated benefit obligation	14,963	15,749	14,177
Net periodic benefit cost
Service cost	459	423	395
Interest cost	533	547	539
Amortization of prior service cost	276	276	276
Recognized net actuarial loss	415	334	303
Net periodic benefit cost	1,683	1,580	1,513
Amounts in accumulated other comprehensive income expected to be recognized in net periodic benefit cost over next fiscal year
Net actuarial loss	41	415	338
Net prior service cost	$ 276	$ 276	$ 276
Minimum [Member] | Supplemental Executive Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.24%	2.48%	2.49%
Amounts in accumulated other comprehensive income expected to be recognized in net periodic benefit cost over next fiscal year
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	2.48%	2.49%	2.49%
Maximum [Member] | Supplemental Executive Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.09%	3.45%	3.94%
Amounts in accumulated other comprehensive income expected to be recognized in net periodic benefit cost over next fiscal year
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	3.45%	3.94%	4.16%