Retirement Plans - Change in Benefit Obligations and Plan Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension plan
Change in benefit obligation - Pension
Benefit obligation at beginning of year	$ 10,099	$ 9,905
Service cost	0	15	$ 223
Interest cost	365	386	406
Actuarial (gain)/assumption changes	837	(1,505)
Benefits paid	(221)	(124)
Settlements paid	0	(1,588)
Benefit obligation at end of year	9,406	10,099	9,905
Accumulated benefit obligation at end of year	9,406	10,099
Change in Plan Assets
Fair value of plan assets at beginning of year	7,819	6,974
Actual return on plan assets	(505)	804
Employer contribution	165	165
Benefits/expenses paid	(221)	(124)
Fair value of plan assets at end of year	7,258	7,819	6,974
Funded status - liability	(2,148)	(2,280)
Amounts recorded in stockholders’ equity
Net actuarial loss	3,162	2,973
Total amount recorded	3,162	2,973
Amount recorded, net taxes	2,277	1,784
SERP
Change in benefit obligation - Pension
Benefit obligation at beginning of year	7,759	8,015
Interest cost	268	287	323
Actuarial (gain)/assumption changes	267	466
Benefits paid	(544)	(444)
Curtailments	0	(565)
Benefit obligation at end of year	7,750	7,759	$ 8,015
Accumulated benefit obligation at end of year	7,750	7,759
Change in Plan Assets
Funded status - liability	(7,750)	(7,759)
Amounts recorded in stockholders’ equity
Net actuarial loss	1,978	1,935
Total amount recorded	1,978	1,935
Amount recorded, net taxes	$ 1,425	$ 1,161