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Retirement Benefits | 12 Months Ended
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Dec. 31, 2022
Retirement Benefits [Abstract] |
Retirement Benefits | Retirement Benefits The Corporation has a defined contribution retirement plan covering substantially all members. The Corporation’s contribution to the plan is based on member eligible earnings and/or member contributions. A portion of the contribution is also based on results of operations, and a portion is contributed in the form of common stock of the Corporation. The following table reconciles the annual contributions:
| 2022 |  | 2021 |  | 2020
Stock contribution | $ | 5.1 |  |  | $ | 7.1 |  |  | $ | 6.9 |
Cash contribution | 25.1 |  |  | 17.8 |  |  | 19.9 |
Total annual contribution | $ | 30.1 |  |  | $ | 25.0 |  |  | $ | 26.8 |

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- Definition The entire disclosure for postemployment benefits, which may include supplemental unemployment benefits, obligations recognized for all types of benefits provided to former or inactive employees, their beneficiaries, and covered dependents after employment but before retirement. Disclosure may also include discussion that an obligation for postemployment benefits is not accrued in accordance with regulation only because the amount cannot be reasonably estimated. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 712 -SubTopic 10 -Section 50 -Paragraph 2 -URI https://asc.fasb.org/extlink&oid=6410195&loc=d3e80090-111668 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 712 -URI https://asc.fasb.org/topic&trid=2197446 + Details
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