Long-term Debt and Short-term Borrowings (Principal Payments on Long-term Debt) (Details) $ in Thousands	Dec. 31, 2018 USD ($)
Debt Instrument [Line Items]
2019	$ 90
2020	400,092
2021	450,096
2022	550,107
2023	109
Thereafter	260,959
Total	1,661,453
Synovus Bank Reporting Unit
Debt Instrument [Line Items]
2019	90
2020	400,092
2021	450,096
2022	250,107
2023	109
Thereafter	959
Total	1,101,453
Parent Company
Debt Instrument [Line Items]
2019	0
2020	0
2021	0
2022	300,000
2023	0
Thereafter	260,000
Total	$ 560,000