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Comprehensive Income (Components of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2021	$ 115,099
Amounts reclassified from AOCI, HTM related	1	$ (2)
Amount reclassified into net income: Net actuarial loss	329	547
Other comprehensive loss	(244,894)	(85,586)
Other comprehensive income, defined pension and post retirement plans	329	547
Ending Balance, March 31, 2022	(129,795)
Available-for-sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2021	185,170
OCI before reclassifications	(206,848)
Amounts reclassified from AOCI, All Other	12,633
Other comprehensive loss	(194,215)
Ending Balance, March 31, 2022	(9,045)
Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2021	180,880
OCI before reclassifications	(275,278)
Amounts reclassified from AOCI	30,055
Other comprehensive loss	(245,223)
Ending Balance, March 31, 2022	(64,343)
Accumulated Other-than-Temporary Impairment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2021	(4,287)
OCI before reclassifications	(68,430)
Amounts reclassified from AOCI, Credit loss related	17,421
Other comprehensive loss	(51,009)
Ending Balance, March 31, 2022	(55,296)
Accumulated Net Unrealized Investment Gain (Loss) [Member] | Held-to-maturity Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2021	(3)
OCI before reclassifications	0
Amounts reclassified from AOCI, HTM related	1
Other comprehensive loss	1
Ending Balance, March 31, 2022	(2)
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2021	(65,781)
OCI before reclassifications, Defined Benefit Pension and Post Retirement Plans	0
Amount reclassified into net income: Net actuarial loss	329
Ending Balance, March 31, 2022	(65,452)
Accumulated other comprehensive income (loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2021	115,099
OCI before reclassifications	(275,278)
Amounts reclassified from AOCI	30,384
Other comprehensive loss	(244,894)	$ (85,586)
Ending Balance, March 31, 2022	$ (129,795)

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Net of tax amount of the reclassification adjustment related to held-to-maturity securities transferred from the available-for-sale category. This amount includes amortization and amounts realized from the disposal of these securities.

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