Comprehensive Income Reclassification out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Provision for Income Taxes	$ 2,475	$ 3,027	$ 6,855	$ 8,735
Net Income	(80)	(56)	(241)	(234)
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Gains and Losses on Available for Sale Securities
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Other Nonoperating Income (Expense)	0	10	0	10
Total before tax	0	10	0	10
Provision for Income Taxes	0	(4)	0	(4)
Net Income	0	6	0	6
Reclassification out of Accumulated Other Comprehensive Income | Accretion of Net Retirement Plan Prior Service (Cost) Credit
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Other Nonoperating Income (Expense)	(27)	3	(81)	8
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss)
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Other Nonoperating Income (Expense)	(81)	(179)	(244)	(537)
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Defined Benefit Plans Adjustment
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	(108)	(176)	(325)	(529)
Provision for Income Taxes	28	114	84	289
Net Income	$ (80)	$ (62)	$ (241)	$ (240)