Condensed Financial Information Of Synovus Financial Corp. (Parent Company Only) - Condensed Statements of Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Condensed Financial Statements, Captions [Line Items]
Net income	$ 757,902	$ 760,467	$ 373,695
Other comprehensive income (loss)	(1,359,796)	(240,956)	92,994
Comprehensive income (loss)	(601,894)	519,511	466,689
Parent Company
Condensed Financial Statements, Captions [Line Items]
Net income	757,902	760,467	373,695
Other comprehensive gain (loss) of bank subsidiary	(1,359,796)	(240,956)	92,994
Other comprehensive income (loss)	(1,359,796)	(240,956)	92,994
Comprehensive income (loss)	$ (601,894)	$ 519,511	$ 466,689