Comprehensive Income Reclassification Out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	$ 45,305	$ 39,855	$ 37,749
Provision for Income Taxes	(9,026)	(10,529)	(11,215)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net of tax	(322)	(691)	(441)
Accumulated Net Unrealized Investment Gain (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Salaries and Employee Benefits		(448)	(22)
Accumulated Net Unrealized Investment Gain (Loss) | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Loss on Securities Transactions, Net	0	(448)	(22)
Total before tax	0	(448)	(22)
Provision for Income Taxes	0	111	9
Net of tax	0	(337)	(13)
Accumulated Defined Benefit Plans Adjustment, Net Prior Service Cost (Credit)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Salaries and Employee Benefits	(108)	11	12
Accumulated Defined Benefit Plans Adjustment, Net Prior Service Cost (Credit) | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Salaries and Employee Benefits	(108)	11	12
Accumulated Defined Benefit Plans Adjustment, Net Unamortized Gain (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Salaries and Employee Benefits	(325)	(411)	(716)
Accumulated Defined Benefit Plans Adjustment, Net Unamortized Gain (Loss) | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Salaries and Employee Benefits	(325)	(411)	(716)
Accumulated Defined Benefit Plans Adjustment | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	(433)	(400)	(704)
Provision for Income Taxes	111	46	276
Net of tax	$ (322)	$ (354)	$ (428)