Retirement Plans - Reconciliation of Changes in Projected Benefit Obligations (Details) - Pension Plans, Defined Benefit [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected benefit obligation at beginning of year	$ 7,167	$ 6,150
Interest cost	272	280	$ 259
Actuarial (gain) loss	(496)	1,235
Expenses paid	(89)	(95)
Benefits paid	(389)	(403)
Projected benefit obligation at end of year	$ 6,465	$ 7,167	$ 6,150