Shareholders' Equity Changes in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Beginning Balance	$ 65,091
Amortization of net unrealized losses on AFS securities transferred to HTM	2,690	$ 3,448	$ 6,285
Ending Balance	27,411	65,091
Unrealized Gains (Losses) on Investment Securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Beginning Balance	81,604	14,864	(43,974)
Other comprehensive loss before reclassifications	(17,948)	65,651	56,239
Amounts reclassified from AOCI (loss)	(25,905)	(2,359)	(3,686)
Amortization of net unrealized losses on AFS securities transferred to HTM	2,690	3,448	6,285
Ending Balance	40,441	81,604	14,864
Net Unrealized (Loss) Gain on Interest Rate Swaps used in Cash Flow Hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Beginning Balance	0	0	0
Other comprehensive loss before reclassifications	0	0	0
Amounts reclassified from AOCI (loss)	(4,817)	0	0
Amortization of net unrealized losses on AFS securities transferred to HTM	0	0	0
Ending Balance	(4,817)	0	0
Unrecognized Pension and Postretirement Plan Income (Costs)
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Beginning Balance	(16,513)	(15,001)	(15,089)
Other comprehensive loss before reclassifications	7,144	(2,532)	(937)
Amounts reclassified from AOCI (loss)	1,156	1,020	1,025
Amortization of net unrealized losses on AFS securities transferred to HTM	0	0	0
Ending Balance	(8,213)	(16,513)	(15,001)
Accumulated Other Comprehensive (Loss) Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Beginning Balance	65,091	(137)	(59,063)
Other comprehensive loss before reclassifications	(10,804)	63,119	55,302
Amounts reclassified from AOCI (loss)	(29,566)	(1,339)	(2,661)
Amortization of net unrealized losses on AFS securities transferred to HTM	2,690	3,448	6,285
Ending Balance	$ 27,411	$ 65,091	$ (137)