| Pay vs Performance Disclosure | 4 Months Ended | 8 Months Ended | 12 Months Ended |
| Apr. 21, 2021 | Dec. 31, 2021 | Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($) |
| Pay vs Performance Disclosure [Table] | | | | | |
| Pay vs Performance [Table Text Block] | | | Year SCT Total Compensation for CEO (1) Compensation Actually Paid (2) to CEO Average SCT Total Compensation for Other NEOs (3) Average Value of Initial Fixed $100 Investment Based on: Net Income Available to Common Share-holders (000s) Adjusted Return on Average Tangible Common Equity (5) Mr. Stelling Mr. Blair Mr. Stelling Mr. Blair Company TSR “Peer Group” (4) TSR 2022 $5,168,041 $2,886,029 $2,648,606 $1,798,148 $95.79 $106.02 $724,739 19.81 % 2021 $5,914,357 5,638,982 $7,708,577 6,846,483 1,546,221 1,935,006 122.12 117.08 727,304 17.76 % 2020 5,229,265 2,845,657 1,538,633 1,103,810 82.58 87.90 340,532 9.12 % | | |
| Company Selected Measure Name | | | Adjusted ROATCE | | |
| Named Executive Officers, Footnote [Text Block] | | | Mr. Stelling served as CEO through April 21, 2021 and Mr. Blair began serving as CEO on April 22, 2021.The other named executive officers are Messrs. Blair, Gregory, Holladay, and Derrick for 2020, Messrs. Gregory, Holladay, and Derrick for 2021, and Messrs. Stelling, Gregory, and Bishop and Ms. Creson for 2022. | | |
| Peer Group Issuers, Footnote [Text Block] | | | Peer Group used for comparison is KBW Regional Bank Index. | | |
| Adjustment To PEO Compensation, Footnote [Text Block] | | | Compensation Actually Paid calculations shown below. Compensation Actually Paid amounts exclude impact of retirement vesting provisions of equity awards. Year-end share amounts include dividend equivalents granted during the year. Kessel D. Stelling Kevin S. Blair Average 2022 SCT Compensation $5,168,041 $2,648,606 Subtract: SCT Equity Amount (2,338,466) (1,102,020) Add: Fair value of equity granted as of 12/31/2022 1,724,378 854,084 Add: Dividends paid Add/Subtract change in unvested equity (1,645,929) (596,790) Add/Subtract change in vested equity during year (21,996) (5,732) Subtract: Forfeited equity 2022 Compensation Paid $2,886,029 $1,798,148 2021 SCT Compensation $5,914,357 $5,638,982 $1,546,221 Subtract: SCT Equity Amount (2,381,490) (3,308,053) (671,048) Add: Fair value of equity granted as of 12/31/2021 3,697,992 4,002,555 811,828 Add: Dividends paid Add/Subtract change in unvested equity 1,582,389 994,807 338,561 Add/Subtract change in vested equity during year 311,873 226,415 47,265 Subtract: Forfeited equity (1,416,544) (708,223) (137,821) 2021 Compensation Paid $7,708,577 $6,846,483 $1,935,006 2020 SCT Compensation $5,229,265 $1,538,633 Subtract: SCT Equity Amount (2,442,364) (678,995) Add: Fair value of equity granted as of 12/31/2020 2,285,319 635,247 Add: Dividends paid Add/Subtract change in unvested equity (576,294) (128,450) Add/Subtract change in vested equity during year (343,420) (73,182) Subtract: Forfeited equity (1,306,850) (189,444) 2020 Compensation Paid $2,845,657 $1,103,810 | | |
| Non-PEO NEO Average Total Compensation Amount | | | $ 2,648,606 | $ 1,546,221 | $ 1,538,633 |
| Non-PEO NEO Average Compensation Actually Paid Amount | | | $ 1,798,148 | 1,935,006 | 1,103,810 |
| Adjustment to Non-PEO NEO Compensation Footnote [Text Block] | | | Compensation Actually Paid calculations shown below. Compensation Actually Paid amounts exclude impact of retirement vesting provisions of equity awards. Year-end share amounts include dividend equivalents granted during the year. Kessel D. Stelling Kevin S. Blair Average 2022 SCT Compensation $5,168,041 $2,648,606 Subtract: SCT Equity Amount (2,338,466) (1,102,020) Add: Fair value of equity granted as of 12/31/2022 1,724,378 854,084 Add: Dividends paid Add/Subtract change in unvested equity (1,645,929) (596,790) Add/Subtract change in vested equity during year (21,996) (5,732) Subtract: Forfeited equity 2022 Compensation Paid $2,886,029 $1,798,148 2021 SCT Compensation $5,914,357 $5,638,982 $1,546,221 Subtract: SCT Equity Amount (2,381,490) (3,308,053) (671,048) Add: Fair value of equity granted as of 12/31/2021 3,697,992 4,002,555 811,828 Add: Dividends paid Add/Subtract change in unvested equity 1,582,389 994,807 338,561 Add/Subtract change in vested equity during year 311,873 226,415 47,265 Subtract: Forfeited equity (1,416,544) (708,223) (137,821) 2021 Compensation Paid $7,708,577 $6,846,483 $1,935,006 2020 SCT Compensation $5,229,265 $1,538,633 Subtract: SCT Equity Amount (2,442,364) (678,995) Add: Fair value of equity granted as of 12/31/2020 2,285,319 635,247 Add: Dividends paid Add/Subtract change in unvested equity (576,294) (128,450) Add/Subtract change in vested equity during year (343,420) (73,182) Subtract: Forfeited equity (1,306,850) (189,444) 2020 Compensation Paid $2,845,657 $1,103,810 | | |
| Compensation Actually Paid vs. Total Shareholder Return [Text Block] | | | Our TSR directly impacts the compensation actually paid to our CEO and other named executive officers, and is the primary driver of the difference between the Summary Compensation Table amounts and Compensation Actually Paid amounts in the above table. This results from the high percentage of compensation delivered through equity awards which are tied directly to share price. Additionally, many of our equity awards included in the Compensation Actually Paid calculation have vesting tied to our absolute TSR (for MRSU grants made through 2019) or relative TSR (for PRSU grants made beginning in 2020). As reflected in the table, our TSR exceeded that of our peers in 2021, but trailed in 2020 and 2022. | | |
| Compensation Actually Paid vs. Net Income [Text Block] | | | While we do not use net income as a direct performance measure in our incentive plan, it impacts the compensation actually paid to our CEO and other named executive officers as it is an input in performance measures in both our annual and long-term incentive plans (adjusted EPS, adjusted ROAA, and adjusted ROATCE). | | |
| Compensation Actually Paid vs. Company Selected Measure [Text Block] | | | Adjusted ROATCE also impacts the compensation actually paid to our CEO and other named executive officers because 50% of the payout under our long-term incentive plan is based upon our adjusted ROATCE during the three-year measurement period. | | |
| Tabular List [Table Text Block] | | | Performance Measures Applicable Plan Adjusted EPS (1) Short-Term Incentive (50%) Adjusted ROAA (1) Short-Term Incentive (25%) Adjusted ROATCE (1) Long-Term Incentive (50%) Relative TSR Long-Term Incentive (50%) | | |
| Total Shareholder Return Amount | | | $ 95.79 | 122.12 | 82.58 |
| Peer Group Total Shareholder Return Amount | | | 106.02 | 117.08 | 87.90 |
| Net Income (Loss) | | | $ 724,739,000 | $ 727,304,000 | $ 340,532,000 |
| Company Selected Measure Amount | | | 0.1981 | 0.1776 | 0.0912 |
| PEO Name | Mr. Stelling | Mr. Blair | Mr. Blair | | Mr. Stelling |
| Additional 402(v) Disclosure [Text Block] | | | (1) For a reconciliation of the foregoing non-GAAP financial measures to the most comparable GAAP measures, please refer to Appendix B of this Proxy Statement. While we utilize several performance measures to align executive compensation with performance, all of those measures are not presented in the Pay for Performance table. Moreover, Synovus generally seeks to incentivize long-term performance, and therefore does not specifically align the Company’s performance measures with compensation that is actually paid (as defined by SEC rules) for a particular year. In accordance with Item 402(v) of Regulation S-K, we are providing the following descriptions of the relationships between information presented in the Pay for Performance table. | | |
| Measure [Axis]: 1 | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Measure Name | | | Adjusted EPS(1) | | |
| Measure [Axis]: 2 | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Measure Name | | | Adjusted ROAA(1) | | |
| Measure [Axis]: 3 | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Measure Name | | | Adjusted ROATCE(1) | | |
| Non-GAAP Measure Description [Text Block] | | | Adjusted Return on Average Tangible Common Equity excludes non-recurring items and certain other items that are not indicative of ongoing operations. For a reconciliation of adjusted ROATCE to the most comparable GAAP measure, please refer to Appendix B o f this Proxy Statement. | | |
| Measure [Axis]: 4 | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Measure Name | | | Relative TSR | | |
| Blair [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| PEO Total Compensation Amount | | | $ 5,168,041 | $ 5,638,982 | |
| PEO Actually Paid Compensation Amount | | | 2,886,029 | 6,846,483 | |
| Stelling [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| PEO Total Compensation Amount | | | | 5,914,357 | $ 5,229,265 |
| PEO Actually Paid Compensation Amount | | | | 7,708,577 | 2,845,657 |
| PEO [Member] | Blair [Member] | Adjustment, Equity Awards Reported Value [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | (2,338,466) | (3,308,053) | |
| PEO [Member] | Blair [Member] | Equity Awards, Granted During the Year [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | 1,724,378 | 4,002,555 | |
| PEO [Member] | Blair [Member] | Equity Awards, Unvested [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | (1,645,929) | 994,807 | |
| PEO [Member] | Blair [Member] | Equity Awards, Vested [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | (21,996) | 226,415 | |
| PEO [Member] | Blair [Member] | Equity Awards, Forfeited [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | | (708,223) | |
| PEO [Member] | Stelling [Member] | Adjustment, Equity Awards Reported Value [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | | (2,381,490) | (2,442,364) |
| PEO [Member] | Stelling [Member] | Equity Awards, Granted During the Year [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | | 3,697,992 | 2,285,319 |
| PEO [Member] | Stelling [Member] | Equity Awards, Unvested [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | | 1,582,389 | (576,294) |
| PEO [Member] | Stelling [Member] | Equity Awards, Vested [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | | 311,873 | (343,420) |
| PEO [Member] | Stelling [Member] | Equity Awards, Forfeited [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | | (1,416,544) | (1,306,850) |
| Non-PEO NEO [Member] | Adjustment, Equity Awards Reported Value [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | (1,102,020) | (671,048) | (678,995) |
| Non-PEO NEO [Member] | Equity Awards, Granted During the Year [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | 854,084 | 811,828 | 635,247 |
| Non-PEO NEO [Member] | Equity Awards, Unvested [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | (596,790) | 338,561 | (128,450) |
| Non-PEO NEO [Member] | Equity Awards, Vested [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | $ (5,732) | 47,265 | (73,182) |
| Non-PEO NEO [Member] | Equity Awards, Forfeited [Member] | | | | | |
| Pay vs Performance Disclosure [Table] | | | | | |
| Adjustment to Compensation Amount | | | | $ (137,821) | $ (189,444) |
