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.

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

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Long-term Debt and Short Term Borrowings (Narrative) (Details) - USD ($)	Dec. 11, 2020	Dec. 31, 2020	Oct. 29, 2020	Feb. 12, 2020	Dec. 31, 2019	Feb. 07, 2019
FHLB Advances
Debt Instrument [Line Items]
Loss on early extinguishment of debt	$ (9,200,000)
FHBL obligations terminated	1,130,000,000
FHLB Advances \| Synovus Bank Reporting Unit
Debt Instrument [Line Items]
FHBL obligations terminated		$ 0			$ 1,300,000,000
Loans Receivable
Debt Instrument [Line Items]
Recorded balance loans receivable					6,190,000,000
3.125% Senior Notes due November 1, 2022
Debt Instrument [Line Items]
Debt, face amount		$ 300,000,000.0
Stated percentage		3.125%
5.90% Subordinated Notes, due February 7, 2029
Debt Instrument [Line Items]
Debt, face amount						$ 300,000,000.0
Stated percentage						5.90%
5.90% Subordinated Notes, due February 7, 2029 \| After February 7, 2029
Debt Instrument [Line Items]
Stated percentage						3.379%
2.289% Fixed-to-Floating Rate Senior Bank Notes due 2023 \| Senior Notes
Debt Instrument [Line Items]
Debt, face amount				$ 400,000,000.0
Stated percentage				228.90%
2.289% Fixed-to-Floating Rate Senior Bank Notes due 2023 \| Senior Notes \| Synovus Bank Reporting Unit
Debt Instrument [Line Items]
Long-term debt		$ 398,594,000			$ 0
Four Percent Subordinated Debt, Due 2030 \| Subordinated Debt
Debt Instrument [Line Items]
Debt, face amount			$ 200.0
Stated percentage			400.00%
5.75% Subordinated Notes Due 2025 \| Subordinated Debt
Debt Instrument [Line Items]
Debt, face amount	$ 250,000,000.0
Stated percentage	5.75%
Loss on early extinguishment of debt	$ (1,300,000)