Comprehensive Income Reclassification out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Provision for income taxes	$ 2,306	$ 2,322	$ 4,456	$ 4,380
Net Income	(176)	(116)	(339)	(161)
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)	(57)	(55)	(113)	(54)
Reclassification out of Accumulated Other Comprehensive Income | Amortization of Net Retirement Plan Actuarial Gain (Loss)
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Other nonoperating income (expense)	(179)	(103)	(342)	(163)
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Defined Benefit Plans Adjustment
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	(236)	(158)	(455)	(217)
Provision for income taxes	60	42	116	56
Net Income	$ (176)	$ (116)	(339)	(161)
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	0
Total before tax			0	0
Provision for income taxes			0	0
Net Income			$ 0	$ 0