Condensed Financial Information Of Synovus Financial Corp. (Parent Company Only) (Condensed Statements Of Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Expenses
Interest expense	$ 291,747	$ 454,835	$ 195,892
Other expenses	1,179,574	1,098,968	829,455
Net income, Before-tax Amount	484,665	765,015	547,354
Net income	373,695	563,780	428,476
Less: Preferred stock dividends	33,163	22,881	17,998
Net income available to common shareholders	340,532	540,899	410,478
Parent Company
Income
Cash dividends received from subsidiaries	547,500	400,000	250,000
Cash distributions received from Synovus Bank	0	0	10,000
Interest income	3,341	5,920	1,703
Other income (loss)	4,966	11,590	(3,904)
Total income	555,807	417,510	257,799
Expenses
Interest expense	42,911	41,328	25,287
Other expenses	10,584	13,528	21,455
Total expenses	53,495	54,856	46,742
Net income, Before-tax Amount	502,312	362,654	211,057
Allocated income tax benefit	(12,202)	(9,753)	(13,690)
Income before equity in undistributed income of subsidiaries	514,514	372,407	224,747
Equity in undistributed income (loss) of subsidiaries	(140,819)	191,373	203,729
Net income	373,695	563,780	428,476
Less: Preferred stock dividends	33,163	22,881	17,998
Net income available to common shareholders	$ 340,532	$ 540,899	$ 410,478