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Comprehensive Income (Components of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2022 | Jun. 30, 2021 | Jun. 30, 2022 | Jun. 30, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |  |
Beginning Balance, December 31, 2021 |  |  |  | $ 115,099 |
Amounts reclassified from AOCI, HTM related |  | $ 0 | $ (2) | 1 | $ (4)
Amount reclassified into net income: Net actuarial loss, Net |  | 330 | 548 | 659 | 1,095
Net current period OCI |  | (206,575) | 34,771 | (451,469) | (50,815)
Net current period OCI, defined benefit pension and post-retirement plans |  | 330 | 548 | 659 | 1,095
Ending Balance, June 30, 2022 |  | (336,370) |  | (336,370) |
Available-for-sale Securities [Member] |  |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |  |
Beginning Balance, December 31, 2021 |  |  |  | 185,170 |
OCI before reclassifications |  |  |  | (382,941) |
Amounts reclassified from AOCI, All Other |  |  |  | 26,987 |
Net current period OCI |  |  |  | (355,954) |
Ending Balance, June 30, 2022 |  | (170,784) |  | (170,784) |
Investments [Member] |  |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |  |
Beginning Balance, December 31, 2021 |  |  |  | 180,880 |
OCI before reclassifications |  |  |  | (508,798) |
Amounts reclassified from AOCI |  |  |  | 56,670 |
Net current period OCI |  |  |  | (452,128) |
Ending Balance, June 30, 2022 |  | (271,248) |  | (271,248) |
Accumulated Other-than-Temporary Impairment [Member] |  |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |  |
Beginning Balance, December 31, 2021 | [1] |  |  | (4,287) |
OCI before reclassifications | [1] |  |  | (125,857) |
Amounts reclassified from AOCI, Credit loss related | [1] |  |  | 29,682 |
Net current period OCI | [1] |  |  | (96,175) |
Ending Balance, June 30, 2022 | [1] | (100,462) |  | (100,462) |
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 |
Net current period OCI |  |  |  | 1 |
Ending Balance, June 30, 2022 |  | (2) |  | (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, Net |  |  |  | 659 |
Ending Balance, June 30, 2022 |  | (65,122) |  | (65,122) |
Accumulated other comprehensive income (loss) [Member] |  |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |  |
Beginning Balance, December 31, 2021 |  |  |  | 115,099 |
OCI before reclassifications |  |  |  | (508,798) |
Amounts reclassified from AOCI |  |  |  | 57,329 |
Net current period OCI |  | (206,575) | $ 34,771 | (451,469) | $ (50,815)
Ending Balance, June 30, 2022 |  | $ (336,370) |  | $ (336,370) |
[1] | 1 Represents change in unrealized loss on securities with credit loss recognized in earnings.

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