Condensed Financial Information Of Synovus Financial Corp. (Parent Company Only) (Condensed Statements Of Income) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Expenses
Interest expense									$ 195,892	$ 139,188	$ 123,623
Other expenses									829,455	821,313	755,923
Income before income taxes	$ 143,854	$ 128,008	$ 142,117	$ 133,375	$ 103,966	$ 152,675	$ 117,791	$ 105,704
Less: Preferred stock dividends and redemption charge									17,998	10,238	10,238
Net income available to common shareholders	$ 101,919	$ 99,330	$ 108,622	$ 100,607	$ 27,046	$ 95,448	$ 73,444	$ 69,298	410,478	265,236	236,546
Parent Company
Income
Cash dividends received from subsidiaries									250,000	283,210	325,000
Cash distributions received from Synovus Bank									10,000	167,790	0
Interest income									1,703	1,443	2,565
Other (loss) income									(3,904)	345	4,595
Total income									257,799	452,788	332,160
Expenses
Interest expense									25,287	43,922	52,831
Other expenses									21,455	33,955	20,652
Total expenses									46,742	77,877	73,483
Income before income taxes									211,057	374,911	258,677
Allocated income tax benefit									(13,690)	(30,421)	(25,628)
Income before equity in undistributed income (loss) of subsidiaries									224,747	405,332	284,305
Equity in undistributed income (loss) of subsidiaries									203,729	(129,858)	(37,521)
Net income (loss) available to controlling interest									428,476	275,474	246,784
Less: Preferred stock dividends and redemption charge									17,998	10,238	10,238
Net income available to common shareholders									$ 410,478	$ 265,236	$ 236,546