Repayments of Long-term Debt, Interest

No definition available.

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Namespace Prefix:	syn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Repayments of Long-term Debt, Principal

+ References

No definition available.

+ Details

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Namespace Prefix:	syn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

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+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.

+ References

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- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Write-off of amounts previously capitalized as debt issuance cost in an extinguishment of debt.

+ References

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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

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- Details

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- Details

Name:	dei_LegalEntityAxis=syn_SynovusBankMember
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Subsequent Event (Details) - USD ($)		12 Months Ended
Subsequent Event (Details) - USD ($)	Feb. 10, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Subsequent Event [Line Items]
Repayments of long-term debt, net		$ 0	$ 2,408,939,000	$ 157,226,000
Subsequent Event \| 2.289% Fixed-to-Floating Rate Senior Bank Notes due 2023 \| Synovus Bank
Subsequent Event [Line Items]
Stated percentage	2.289%
Debt, face amount	$ 400,000,000
Repayments of long-term debt, net	405,300,000
Repayments of long-term debt, principal	400,000,000
Repayments of long-term debt, interest	4,600,000
Write off debt issuance cost	$ 675,000