Debt Instrument, Interest Rate Period

No definition available.

Name:	syn_DebtInstrumentInterestRatePeriod
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Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Balance Type:	na
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- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

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+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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

- Definition

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

+ References

+ Details

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

- Definition

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.

+ References

No definition available.

+ Details

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

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Balance Type:	credit
Period Type:	instant

- Definition

Amount of long-term debt classified as other.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

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

- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of subordinated debt (with initial maturities beyond one year or beyond the operating cycle if longer). Subordinated debt places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of uncollateralized debt obligations (with maturities initially due after one year or beyond the operating cycle if longer).

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Period Type:	instant

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Long-term Debt and Short-term Borrowings - Schedule of Long-term Debt Instruments (Details) - USD ($)		12 Months Ended
	Feb. 10, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Long-term debt		$ 1,204,229,000	$ 1,202,494,000
Repayments of long-term debt, net		0	2,408,939,000	$ 157,226,000
Synovus Bank
Debt Instrument [Line Items]
Other long-term debt		0	145,000
Long-term debt		596,895,000	596,088,000
Synovus Bank \| 2.289% Fixed-to-Floating Rate Senior Bank Notes due 2023 \| Subsequent Event
Debt Instrument [Line Items]
Repayments of long-term debt, net	$ 405,300,000
Stated percentage	2.289%
Debt, face amount	$ 400,000,000
Synovus Bank \| Four Percent Subordinated Notes, Due October 29, 2030
Debt Instrument [Line Items]
Subordinated notes		$ 197,626,000	197,349,000
Stated percentage		4.00%
Debt, face amount		$ 200,000,000.0
Interest rate period		5 years
Synovus Bank \| Four Percent Subordinated Notes, Due October 29, 2030 \| US Treasury Rate
Debt Instrument [Line Items]
Basis spread on variable rate		3.625%
Synovus Bank \| Senior Notes \| 2.289% Fixed-to-Floating Rate Senior Bank Notes due 2023
Debt Instrument [Line Items]
Long-term debt		$ 399,269,000	398,594,000
Stated percentage		2.289%
Debt, face amount		$ 400,000,000.0
Interest rate period		2 years
Synovus Bank \| Senior Notes \| 2.289% Fixed-to-Floating Rate Senior Bank Notes due 2023 \| Secured Overnight Financing Rate (SOFR)
Debt Instrument [Line Items]
Basis spread on variable rate		0.945%
Parent Company
Debt Instrument [Line Items]
Long-term debt		$ 607,334,000	606,406,000
Repayments of long-term debt, net		0	250,000,000	$ 0
Parent Company \| 5.90% Subordinated Notes, due February 7, 2029
Debt Instrument [Line Items]
Subordinated notes		$ 297,855,000	297,553,000
Stated percentage		5.90%
Debt, face amount		$ 300,000,000.0
Interest rate period		5 years
Parent Company \| 5.90% Subordinated Notes, due February 7, 2029 \| Five-Year Mid Swap Rate
Debt Instrument [Line Items]
Basis spread on variable rate		3.379%
Parent Company \| LIBOR 1.80% debentures, due June 15, 2035
Debt Instrument [Line Items]
Unsecured debt		$ 10,000,000	$ 10,000,000
Stated percentage		1.80%
Debt, face amount		$ 10,000,000.0
Interest rate at period end		2.00%	2.02%
Parent Company \| Senior Notes \| 3.125% Senior Notes due November 1, 2022
Debt Instrument [Line Items]
Long-term debt		$ 299,479,000	$ 298,853,000
Stated percentage		3.125%
Debt, face amount		$ 300,000,000.0