Retirement Plans - Change in Benefit Obligations and Plan Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pension plan
Change in benefit obligation - Pension
Benefit obligation at beginning of year	$ 9,406	$ 10,099
Service cost	0	0	$ 15
Interest cost	389	365	386
Actuarial (gain)/assumption changes	(1,161)	837
Benefits paid	(246)	(221)
Settlements paid	0	0
Benefit obligation and accumulated benefit obligation at end of year	10,710	9,406	10,099
Accumulated benefit obligation at end of year	10,710	9,406
Change in Plan Assets
Fair value of plan assets at beginning of year	7,258	7,819
Actual return on plan assets	1,744	(505)
Employer contribution	165	165
Benefits/expenses paid	(247)	(221)
Fair value of plan assets at end of year	8,920	7,258	7,819
Funded status - liability	(1,790)	(2,148)
Amounts recorded in stockholders’ equity
Net actuarial loss	3,027	3,162
Total amount recorded	3,027	3,162
Amount recorded, net taxes	2,180	2,277
SERP
Change in benefit obligation - Pension
Benefit obligation at beginning of year	7,750	7,759
Interest cost	303	268	287
Actuarial (gain)/assumption changes	486	267
Benefits paid	(528)	(544)
Curtailments	0	0
Benefit obligation and accumulated benefit obligation at end of year	8,011	7,750	$ 7,759
Accumulated benefit obligation at end of year	8,011	7,750
Change in Plan Assets
Funded status - liability	(8,011)	(7,750)
Amounts recorded in stockholders’ equity
Net actuarial loss	2,402	1,978
Total amount recorded	2,402	1,978
Amount recorded, net taxes	$ 1,730	$ 1,425