Capital Ratios (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018	Jun. 30, 2018
Capital ratios
Capital conversion buffer common equity Tier 1 of risk-weighted assets (as a percent)		2.50%
Common equity Tier 1 to risk-weighted assets
Actual, Capital Amount	$ 1,323,535		$ 1,335,826	$ 1,324,901
Actual, Ratio (as a percent)	11.58%		12.05%	12.00%
Minimum capital required, Ratio (as a percent)	4.50%
Required to be considered well capitalized, Capital Amount	$ 742,959		$ 720,844	$ 718,070
Required to be considered well capitalized, Ratio (as a percent)	6.50%		6.50%	6.50%
Tier I capital to risk-weighted assets
Actual, Capital Amount	$ 1,435,471		$ 1,447,428	$ 1,436,170
Actual, Ratio (as a percent)	12.56%		13.05%	13.00%
Minimum capital required, Ratio (as a percent)	6.00%		4.00%
Required to be considered well capitalized, Capital Amount	$ 914,411		$ 887,192	$ 883,779
Required to be considered well capitalized, Ratio (as a percent)	8.00%		8.00%	8.00%
Total capital to risk-weighted assets
Actual, Capital Amount	$ 1,494,019		$ 1,503,561	$ 1,488,805
Actual, Ratio (as a percent)	13.07%		13.56%	13.48%
Minimum capital required, Ratio (as a percent)	8.00%
Required to be considered well capitalized, Capital Amount	$ 1,143,013		$ 1,108,990	$ 1,104,723
Required to be considered well capitalized, Ratio (as a percent)	10.00%		10.00%	10.00%
Tier I capital to average assets (leverage ratio)
Actual, Capital Amount	$ 1,435,471		$ 1,447,428	$ 1,436,170
Actual, Ratio (as a percent)	9.99%		10.65%	10.62%
Minimum capital required, Ratio (as a percent)	4.00%
Required to be considered well capitalized, Capital Amount	$ 718,675		$ 679,383	$ 676,086
Required to be considered well capitalized, Ratio (as a percent)	5.00%		5.00%	5.00%
Phase-In Schedule
Common equity Tier 1 to risk-weighted assets
Minimum capital required, Capital Amount	$ 800,109		$ 706,981	$ 704,261
Minimum capital required, Ratio (as a percent)	7.00%		6.38%	6.38%
Tier I capital to risk-weighted assets
Minimum capital required, Capital Amount	$ 971,561		$ 873,330	$ 869,970
Minimum capital required, Ratio (as a percent)	8.50%		7.88%	7.88%
Total capital to risk-weighted assets
Minimum capital required, Capital Amount	$ 1,200,164		$ 1,095,128	$ 1,090,914
Minimum capital required, Ratio (as a percent)	10.50%		9.88%	9.88%
Tier I capital to average assets (leverage ratio)
Minimum capital required, Capital Amount	$ 574,940		$ 543,506	$ 540,869
Minimum capital required, Ratio (as a percent)	4.00%		4.00%	4.00%
Fully Phased-In
Common equity Tier 1 to risk-weighted assets
Minimum capital required, Capital Amount	$ 800,109		$ 776,293	$ 773,306
Minimum capital required, Ratio (as a percent)	7.00%		7.00%	7.00%
Tier I capital to risk-weighted assets
Minimum capital required, Capital Amount	$ 971,561		$ 942,642	$ 939,015
Minimum capital required, Ratio (as a percent)	8.50%		8.50%	8.50%
Total capital to risk-weighted assets
Minimum capital required, Capital Amount	$ 1,200,164		$ 1,164,440	$ 1,159,960
Minimum capital required, Ratio (as a percent)	10.50%		10.50%	10.50%
Tier I capital to average assets (leverage ratio)
Minimum capital required, Capital Amount	$ 574,940		$ 543,506	$ 540,869
Minimum capital required, Ratio (as a percent)	4.00%		4.00%	4.00%
South State Bank (the Bank)
Common equity Tier 1 to risk-weighted assets
Actual, Capital Amount	$ 1,419,395		$ 1,427,764	$ 1,413,812
Actual, Ratio (as a percent)	12.42%		12.87%	12.80%
Required to be considered well capitalized, Capital Amount	$ 742,971		$ 720,902	$ 718,084
Required to be considered well capitalized, Ratio (as a percent)	6.50%		6.50%	6.50%
Tier I capital to risk-weighted assets
Actual, Capital Amount	$ 1,419,395		$ 1,427,764	$ 1,413,812
Actual, Ratio (as a percent)	12.42%		12.87%	12.80%
Required to be considered well capitalized, Capital Amount	$ 914,426		$ 887,264	$ 883,796
Required to be considered well capitalized, Ratio (as a percent)	8.00%		8.00%	8.00%
Total capital to risk-weighted assets
Actual, Capital Amount	$ 1,477,943		$ 1,483,897	$ 1,466,447
Actual, Ratio (as a percent)	12.93%		13.38%	13.27%
Required to be considered well capitalized, Capital Amount	$ 1,143,033		$ 1,109,080	$ 1,104,745
Required to be considered well capitalized, Ratio (as a percent)	10.00%		10.00%	10.00%
Tier I capital to average assets (leverage ratio)
Actual, Capital Amount	$ 1,419,395		$ 1,427,764	$ 1,413,812
Actual, Ratio (as a percent)	9.88%		10.51%	10.46%
Required to be considered well capitalized, Capital Amount	$ 718,475		$ 679,234	$ 675,907
Required to be considered well capitalized, Ratio (as a percent)	5.00%		5.00%	5.00%
South State Bank (the Bank) | Phase-In Schedule
Common equity Tier 1 to risk-weighted assets
Minimum capital required, Capital Amount	$ 800,123		$ 707,039	$ 704,275
Minimum capital required, Ratio (as a percent)	7.00%		6.38%	6.38%
Tier I capital to risk-weighted assets
Minimum capital required, Capital Amount	$ 971,578		$ 873,401	$ 869,986
Minimum capital required, Ratio (as a percent)	8.50%		7.88%	7.88%
Total capital to risk-weighted assets
Minimum capital required, Capital Amount	$ 1,200,184		$ 1,095,217	$ 1,090,935
Minimum capital required, Ratio (as a percent)	10.50%		9.88%	9.88%
Tier I capital to average assets (leverage ratio)
Minimum capital required, Capital Amount	$ 574,780		$ 543,387	$ 540,726
Minimum capital required, Ratio (as a percent)	4.00%		4.00%	4.00%
South State Bank (the Bank) | Fully Phased-In
Common equity Tier 1 to risk-weighted assets
Minimum capital required, Capital Amount	$ 800,123		$ 776,356	$ 773,321
Minimum capital required, Ratio (as a percent)	7.00%		7.00%	7.00%
Tier I capital to risk-weighted assets
Minimum capital required, Capital Amount	$ 971,578		$ 942,718	$ 939,033
Minimum capital required, Ratio (as a percent)	8.50%		8.50%	8.50%
Total capital to risk-weighted assets
Minimum capital required, Capital Amount	$ 1,200,184		$ 1,164,534	$ 1,159,982
Minimum capital required, Ratio (as a percent)	10.50%		10.50%	10.50%
Tier I capital to average assets (leverage ratio)
Minimum capital required, Capital Amount	$ 574,780		$ 543,387	$ 540,726
Minimum capital required, Ratio (as a percent)	4.00%		4.00%	4.00%