Condensed Financial Information Of Synovus Financial Corp. (Parent Company Only) (Condensed Statements of Cash Flows) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Adjustments to reconcile net income to net cash provided by operating activities:
Net cash provided by operating activities	$ 467,767	$ 447,542	$ 387,218
Investing Activities
Net cash used in investing activities	(1,105,595)	(2,109,273)	(1,166,774)
Financing Activities
Repurchases and agreements to repurchase shares of common stock	(263,084)	(199,221)	(88,113)
Repayments on long-term debt	(2,263,688)	(823,899)	(400,781)
Proceeds from issuance of long-term debt	1,875,000	871,644	510,000
Net cash provided by financing activities	665,911	1,543,334	795,415
Increase (decrease) in cash and cash equivalents	28,083	(118,397)	15,859
Cash and cash equivalents at beginning of year	367,092	485,489	469,630
Cash and cash equivalents at end of year	395,175	367,092	485,489
Income tax payments, net	9,340	10,514	5,971
Interest paid	123,560	115,795	109,549
Parent Company [Member]
Operating Activities
Net income	246,784	226,082	195,249
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in undistributed loss (income) of subsidiaries	37,521	(30,847)	(39,491)
Deferred income tax expense (benefit)	17,989	(2,506)	(5,041)
Net increase (decrease) in other liabilities	7,746	(1,709)	(22,323)
Net (increase) decrease in other assets	(9,214)	1,045	14,226
Other, net	(1,648)	(178)	(2,041)
Net cash provided by operating activities	299,178	191,887	140,579
Investing Activities
Net cash received (used) in acquisitions/dispositions	(3,408)	0	0
Net decrease in short-term notes receivable from non-bank subsidiaries	31,800	10,000	39,000
Net cash used in investing activities	28,392	10,000	39,000
Financing Activities
Dividends paid to common and preferred shareholders	(69,663)	(65,592)	(53,043)
Repurchases and agreements to repurchase shares of common stock	(263,084)	(199,221)	(88,113)
Repayments on long-term debt	(130,048)	(48,553)	0
Proceeds from issuance of long-term debt	0	246,644	0
Net cash provided by financing activities	(462,795)	(66,722)	(141,156)
Increase (decrease) in cash and cash equivalents	(135,225)	135,165	38,423
Cash and cash equivalents at beginning of year	389,475	254,310	215,887
Cash and cash equivalents at end of year	254,250	389,475	254,310
Income tax payments, net	9,500	8,700	4,800
Interest paid	$ 53,100	$ 46,900	$ 46,900