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, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Expenses
Interest expense									$ 123,623	$ 118,644	$ 109,408
Other expenses									755,923	717,655	744,998
Income before income taxes	$ 108,068	$ 102,620	$ 94,031	$ 83,730	$ 90,741	$ 93,986	$ 88,034	$ 85,812	388,451	358,573	302,559
Dividends on preferred stock									10,238	10,238	10,238
Net income available to common shareholders	$ 65,990	$ 62,686	$ 57,898	$ 49,972	$ 55,839	$ 55,369	$ 53,233	$ 51,404	236,546	215,844	185,011
Parent Company [Member]
Income
Cash dividends received from Synovus Bank									325,000	199,904	90,626
Cash distributions received from Synovus Bank									0	25,096	91,374
Interest income									2,565	8,865	14,262
Other income									4,595	(337)	(932)
Total income									332,160	233,528	195,330
Expenses
Interest expense									52,831	46,585	45,726
Other expenses									20,652	10,516	10,337
Total expenses									73,483	57,101	56,063
Income before income taxes									258,677	176,427	139,267
Allocated income tax benefit									(25,628)	(18,808)	(16,491)
Income before equity in undistributed income (loss) of subsidiaries									284,305	195,235	155,758
Equity in undistributed income (loss) of subsidiaries									(37,521)	30,847	39,491
Net income (loss) available to controlling interest									246,784	226,082	195,249
Dividends on preferred stock									10,238	10,238	10,238
Net income available to common shareholders									$ 236,546	$ 215,844	$ 185,011