Retirement Plans - Change in Benefit Obligations and Plan Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Pension plan
Change in benefit obligation - Pension
Benefit obligation at beginning of year	$ 11,051	$ 9,326
Service cost	265	248	$ 359
Interest cost	466	392	402
Actuarial gain/assumption changes	(1,239)	2,804
Benefits paid	(33)	(1,719)
Settlements paid	(1,540)	0
Benefit obligation at end of year	8,970	11,051	9,326
Accumulated benefit obligation at end of year	7,661	9,473
Change in Plan Assets
Fair value of plan assets at beginning of year	7,972	8,633
Actual return on plan assets	(142)	407
Employer contribution	450	650
Benefits/expenses paid	(33)	(1,718)
Settlements paid	(1,540)	0
Fair value of plan assets at end of year	6,707	7,972	8,633
Funded status - liability	(2,263)	(3,079)
Amounts recorded in stockholders’ equity
Net actuarial (gain) loss	3,123	4,453
Prior service cost	(90)	(119)
Total amount recorded	3,033	4,334
Amount recorded, net taxes	1,820	2,600
SERP
Change in benefit obligation - Pension
Benefit obligation at beginning of year	7,431	6,131
Service cost	0	26	318
Interest cost	278	258	219
Actuarial gain/assumption changes	726	1,399
Benefits paid	(436)	(383)
Benefit obligation at end of year	7,999	7,431	$ 6,131
Accumulated benefit obligation at end of year	7,117	6,937
Change in Plan Assets
Funded status - liability	(7,999)	(7,431)
Amounts recorded in stockholders’ equity
Net actuarial (gain) loss	2,462	2,072
Prior service cost	0	0
Total amount recorded	2,462	2,072
Amount recorded, net taxes	$ 1,477	$ 1,243