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Regulatory & Capital Matters (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019
Regulatory & Capital Matters
Tier 1 capital leverage ratio (as a percent)	10.21	11.93
Risk-based capital ratio (as a percent)	14.26	14.53
Phase out of impact of allowance for credit loss	$ 3.8
Deferment of impact on rretained earnings	5.7
Change in allowance for credit loss	$ 10.4
Subsidiaries [Member]
Regulatory & Capital Matters
Tier 1 capital leverage ratio (as a percent)	10.74	12.50
Risk-based capital ratio (as a percent)	15.00	15.23
Minimum [Member] | Subsidiaries [Member]
Regulatory & Capital Matters
Tier 1 capital leverage ratio (as a percent)	8
Risk-based capital ratio (as a percent)	12

X

- Definition

The amount of increase (decrease) in allowance for credit losses.

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- Definition

The amount of deferment of cumulative effect on retained earnings due to adoption of new accounting standards.

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- Definition

The amount of phase out the impact of allowance for credit loss.

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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

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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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

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