Condensed Financial Information of Synovus Financial Corp. (Parent Company only) - Condensed Statements Of Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Expense
Interest expense	$ 1,233,703	$ 278,887	$ 120,396
Other expense	1,335,424	1,157,506	1,099,904
Net income attributable to Synovus Financial Corp.	543,705	757,902	760,467
Net income available to common shareholders	507,755	724,739	727,304
Parent Company
Income
Cash dividends received from subsidiaries	435,000	350,000	420,000
Interest income	6,129	1,841	777
Other income (loss)	(101)	(7,203)	1,070
Total income	441,028	344,638	421,847
Expense
Interest expense	36,849	34,154	27,616
Other expense	12,494	17,804	10,300
Total expense	49,343	51,958	37,916
Income before income taxes and equity in undistributed income of subsidiaries	391,685	292,680	383,931
Allocated income tax benefit	(10,026)	(16,667)	(7,834)
Income before equity in undistributed income of subsidiaries	401,711	309,347	391,765
Equity in undistributed income (loss) of subsidiaries	141,994	448,555	368,702
Net income attributable to Synovus Financial Corp.	543,705	757,902	760,467
Less: Preferred stock dividends	35,950	33,163	33,163
Net income available to common shareholders	$ 507,755	$ 724,739	$ 727,304