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Data Type:	xbrli:sharesItemType
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Period Type:	duration

Represents the weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

No definition available.

Name:	ucbi_Share-BasedCompensationArrangementByShare-BasedPaymentAwardEquityInstrumentsOtherThanOptionsExpiredWeightedAverageGrantDateFairValue
Namespace Prefix:	ucbi_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	duration

This element represents share based compensation arrangement by share based payment award equity instruments other than option exercisable number.

No definition available.

Name:	ucbi_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExercisableNumber
Namespace Prefix:	ucbi_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

This element represents share based compensation arrangement by share based payment award equity instruments other than options exercisable weighted average grant date fair value.

No definition available.

Name:	ucbi_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExercisableWeightedAverageGrantDateFairValue
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Data Type:	dtr-types:perShareItemType
Balance Type:	na
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The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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Data Type:	xbrli:sharesItemType
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Period Type:	duration

Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	duration

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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Data Type:	xbrli:sharesItemType
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Period Type:	duration

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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Data Type:	dtr-types:perShareItemType
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Period Type:	duration

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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Period Type:	instant

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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Data Type:	xbrli:stringItemType
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Period Type:	duration

Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

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Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- References

No definition available.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward
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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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Data Type:	xbrli:sharesItemType
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Period Type:	duration

The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue
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Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	duration

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Number of options or other stock instruments for which the right to exercise has lapsed under the terms of the plan agreements.

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Gross number of share options (or share units) granted during the period.

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue
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Number of options outstanding, including both vested and non-vested options.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Period Type:	instant

- References

No definition available.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Data Type:	dtr-types:perShareItemType
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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options of the plan that expired.

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Data Type:	dtr-types:perShareItemType
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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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Data Type:	dtr-types:perShareItemType
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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Data Type:	dtr-types:perShareItemType
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Intrinsic value of outstanding award under share-based payment arrangement. Excludes share and unit options.

No definition available.

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Intrinsic value of vested award under share-based payment arrangement. Excludes share and unit options.

No definition available.

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Data Type:	xbrli:monetaryItemType
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Period Type:	duration

Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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Data Type:	xbrli:durationItemType
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Number of share options (or share units) exercised during the current period.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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