Condensed Financial Information Of Synovus Financial Corp. (Parent Company Only) (Condensed Statements of Cash Flows) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Adjustments to reconcile net income to net cash provided by operating activities:
Net cash provided by operating activities	$ 447,542	$ 387,218	$ 605,101
Investing Activities
Net cash used in investing activities	(2,109,273)	(1,166,774)	(27,586)
Financing Activities
Repurchases and agreements to repurchase shares of common stock	(199,221)	(88,113)	0
Repayments on long-term debt	(823,899)	(400,781)	(307,571)
Proceeds from issuance of long-term debt	871,644	510,000	617,500
Proceeds from issuance of Series C Preferred Stock, net of issuance costs	0	0	125,862
Redemption of Series A Preferred Stock	0	0	(967,870)
Proceeds from issuance of common stock, net of issuance costs	0	0	175,174
Net cash provided by (used in) financing activities	1,543,334	795,415	(722,515)
(Decrease) increase in cash and cash equivalents	(118,397)	15,859	(145,000)
Cash and cash equivalents at beginning of year	485,489	469,630	614,630
Cash and cash equivalents at end of year	367,092	485,489	469,630
Income tax payments, net	10,514	5,971	2,577
Interest paid	115,795	109,549	121,291
Parent Company [Member]
Operating Activities
Net income	226,082	195,249	159,383
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in undistributed (income) loss of subsidiaries	(30,847)	(39,491)	495,459
Deferred income tax benefit	(2,506)	(5,041)	(11,375)
Net (decrease) increase in other liabilities	(1,709)	(22,323)	11,845
Net decrease (increase) in other assets	1,045	14,226	(11,238)
Other, net	(178)	(2,041)	(2,183)
Net cash provided by operating activities	191,887	140,579	641,891
Investing Activities
Net decrease in short-term notes receivable from non-bank subsidiaries	10,000	39,000	5,768
Net cash used in investing activities	10,000	39,000	5,768
Financing Activities
Dividends paid to common and preferred shareholders	(65,592)	(53,043)	(72,898)
Repurchases and agreements to repurchase shares of common stock	(199,221)	(88,113)	0
Repayments on long-term debt	(48,553)	0	(74,178)
Proceeds from issuance of long-term debt	246,644	0	0
Proceeds from issuance of Series C Preferred Stock, net of issuance costs	0	0	125,862
Redemption of Series A Preferred Stock	0	0	(967,870)
Proceeds from issuance of common stock, net of issuance costs	0	0	175,174
Net cash provided by (used in) financing activities	(66,722)	(141,156)	(813,910)
(Decrease) increase in cash and cash equivalents	135,165	38,423	(166,251)
Cash and cash equivalents at beginning of year	254,310	215,887	382,138
Cash and cash equivalents at end of year	389,475	254,310	215,887
Income tax payments, net	8,700	4,800	1,500
Interest paid	$ 46,900	$ 46,900	$ 49,100