Other Comprehensive Income/(Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Pre-Tax Amount
Other Comprehensive Income/(Loss), Pre-Tax Amount	$ 281	$ 2,804	$ 26,833	$ 20,075
Tax (Expense) Benefit
Other Comprehensive Income/(Loss), Tax (Expense) Benefit	(60)	(598)	(5,710)	(4,281)
Net of Tax Amount
Other Comprehensive Income/(Loss), Net of Tax Amount	221	2,206	21,123	15,794
Pension settlement charge	700		700
Accumulated Net Investment Gain (Loss) Attributable to Parent
Pre-Tax Amount
Change in net unrealized gains/(losses) on debt securities available-for-sale	(882)	2,350	24,883	18,716
Reclassification adjustment for net (gains)/losses on debt securities available-for-sale included in net income	0	0	(142)	0
Tax (Expense) Benefit
Change in net unrealized gains/(losses) on debt securities available-for-sale	188	(501)	(5,294)	(3,991)
Reclassification adjustment for net (gains)/losses on debt securities available-for-sale included in net income	0	0	30	0
Net of Tax Amount
Change in net unrealized gains/(losses) on debt securities available-for-sale	(694)	1,849	19,589	14,725
Reclassification adjustment for net (gains)/losses on debt securities available-for-sale included in net income	0	0	(112)	0
Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent
Pre-Tax Amount
Other Comprehensive Income/(Loss), Pre-Tax Amount	1,163	454	2,092	1,359
Tax (Expense) Benefit
Other Comprehensive Income/(Loss), Tax (Expense) Benefit	(248)	(97)	(446)	(290)
Net of Tax Amount
Other Comprehensive Income/(Loss), Net of Tax Amount	$ 915	$ 357	$ 1,646	$ 1,069