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Regulatory & Capital Matters (Details) $ in Millions | 9 Months Ended |  |
--- | --- | --- | ---
Sep. 30, 2021 USD ($) | Dec. 31, 2020 | Jan. 01, 2020 USD ($)
Regulatory & Capital Matters |  |  |
Tier 1 capital leverage ratio (as a percent) | 9.81 | 10.21 |
Risk-based capital ratio (as a percent) | 17.80 | 14.26 |
Phase out of impact of allowance for credit loss |  |  | $ 3.8
Deferment of impact on retained earnings | $ 4.2 |  |
Subsidiaries [Member] |  |  |
Regulatory & Capital Matters |  |  |
Tier 1 capital leverage ratio (as a percent) | 10.83 | 10.74 |
Risk-based capital ratio (as a percent) | 16.69 | 15.00 |
Tier One leverage ratio, basis point increase (as a percent) | 0.09% |  |
Risk-based capital ratio, basis point increase (as a percent) | 1.68% |  |
Minimum [Member] | Subsidiaries [Member] |  |  |
Regulatory & Capital Matters |  |  |
Tier 1 capital leverage ratio (as a percent) | 8 |  |
Risk-based capital ratio (as a percent) | 12 |  |
Tier 1 capital leverage ratio, board-designated threshold | 8.00% |  |
Total Capital Ratio, board-designated threshold (as a percent) | 12.00% |  |

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- Definition Ratio of total risk-based capital to risk-weighted assets as defined by regulatory framework. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
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- Definition Ratio of Tier 1 capital to average assets as defined by regulatory framework. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
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