Regulatory Capital (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Capital conservation buffer	2.50%
Capital conservation buffer period	3 years
Well-capitalized status,Tier 1 capital ratio	8.00%
Significant subsidiary, assets or net income as percentage of consolidated total, threshold	10.00%
Tier I capital
Tier I capital, Actual	$ 2,660,016	$ 2,543,625
Tier I capital, For Capital Adequacy Purposes	1,538,637	1,051,909
Common equity tier I capital (transitional)
Common equity tier 1 capital (transitional), Actual	2,660,016
Common equity tier 1 capital (transitional), For Capital Adequacy Purposes	1,153,977
Total risk-based capital
Total risk-based capital, Actual	3,255,758	2,987,406
Total risk-based capital, For Capital Adequacy Purposes	$ 2,051,515	$ 1,874,516
Tier I capital ratio
Tier I capital ratio, Actual	10.37%	10.86%
Tier I capital ratio, For Capital Adequacy Purposes	6.00%	4.00%
Common equity tier I capital ratio (transitional)
Common equity tier I capital ratio (transitional), Actual	10.37%	10.74%
Common equity tier I capital ratio (transitional), For Capital Adequacy Purposes	4.50%
Common equity tier I capital ratio (transitional), To Be Well Capitalized Under Prompt Corrective Action Provisions	6.50%
Total risk-based capital ratio
Total risk-based capital ratio, Actual	12.70%	12.75%
Total risk-based capital ratio, For Capital Adequacy Purposes	8.00%	8.00%
Total risk-based capital ratio, To Be Well Capitalized Under Prompt Corrective Action Provisions	10.00%
Leverage ratio
Leverage ratio, Actual	9.43%	9.67%
Leverage ratio, For Capital Adequacy Purposes	4.00%	4.00%
Leverage ratio, To Be Well Capitalized Under Prompt Corrective Action Provisions	5.00%
Minimum [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Capital conservation buffer	0.625%
Synovus Bank [Member]
Tier I capital
Tier I capital, Actual	$ 3,136,132	$ 2,988,189
Tier I capital, For Capital Adequacy Purposes	1,535,541	1,049,257
Tier I capital, To Be Well Capitalized Under Prompt Corrective Action Provisions	2,047,388	1,405,071
Common equity tier I capital (transitional)
Common equity tier 1 capital (transitional), Actual	3,136,132
Common equity tier 1 capital (transitional), For Capital Adequacy Purposes	1,151,656
Common equity tier 1 capital (transitional), To Be Well Capitalized Under Prompt Corrective Action Provisions	1,663,503
Total risk-based capital
Total risk-based capital, Actual	3,390,764	3,251,836
Total risk-based capital, For Capital Adequacy Purposes	2,047,388	1,873,428
Total risk-based capital, To Be Well Capitalized Under Prompt Corrective Action Provisions	$ 2,559,235	$ 2,341,785
Tier I capital ratio
Tier I capital ratio, Actual	12.25%	12.76%
Tier I capital ratio, For Capital Adequacy Purposes	6.00%	4.00%
Tier I capital ratio, To Be Well Capitalized Under Prompt Corrective Action Provisions	8.00%	6.00%
Common equity tier I capital ratio (transitional)
Common equity tier I capital ratio (transitional), Actual	12.25%
Common equity tier I capital ratio (transitional), For Capital Adequacy Purposes	4.50%
Common equity tier I capital ratio (transitional), To Be Well Capitalized Under Prompt Corrective Action Provisions	6.50%
Total risk-based capital ratio
Total risk-based capital ratio, Actual	13.25%	13.89%
Total risk-based capital ratio, For Capital Adequacy Purposes	8.00%	8.00%
Total risk-based capital ratio, To Be Well Capitalized Under Prompt Corrective Action Provisions	10.00%	10.00%
Leverage ratio
Leverage ratio, Actual	11.15%	11.39%
Leverage ratio, For Capital Adequacy Purposes	4.00%	4.00%
Leverage ratio, To Be Well Capitalized Under Prompt Corrective Action Provisions	5.00%	5.00%