Capital Ratios (Details) - USD ($) $ in Thousands	Jan. 01, 2019	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Common equity Tier 1 to risk-weighted assets
Actual, Capital Amount		$ 765,032	$ 711,577	$ 693,121
Actual, Ratio (as a percent)		11.48%	11.84%	11.82%
Minimum capital required, Ratio (as a percent)		4.50%
Required to be considered well capitalized, Capital Amount		$ 428,792	$ 390,624	$ 381,200
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		$ 817,746	$ 763,590	$ 743,805
Actual, Ratio (as a percent)		12.27%	12.71%	12.68%
Minimum capital required, Ratio (as a percent)		6.00%	4.00%
Required to be considered well capitalized, Capital Amount		$ 527,744	$ 480,768	$ 469,169
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		$ 858,813	$ 801,745	$ 783,605
Actual, Ratio (as a percent)		12.89%	13.34%	13.36%
Minimum capital required, Ratio (as a percent)		8.00%
Required to be considered well capitalized, Capital Amount		$ 659,681	$ 600,961	$ 586,461
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		$ 817,746	$ 763,590	$ 743,805
Actual, Ratio (as a percent)		9.74%	9.31%	9.32%
Minimum capital required, Ratio (as a percent)		4.00%
Required to be considered well capitalized, Capital Amount		$ 416,984	$ 410,107	$ 398,937
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		$ 338,086	$ 270,432	$ 263,907
Minimum capital required, Ratio (as a percent)		5.125%	4.50%	4.50%
Tier I capital to risk-weighted assets
Minimum capital required, Capital Amount		$ 395,808	$ 360,576	$ 351,877
Minimum capital required, Ratio (as a percent)		6.00%	6.00%	6.00%
Total capital to risk-weighted assets
Minimum capital required, Capital Amount		$ 527,744	$ 480,768	$ 469,169
Minimum capital required, Ratio (as a percent)		8.00%	8.00%	8.00%
Tier I capital to average assets (leverage ratio)
Minimum capital required, Capital Amount		$ 333,587	$ 328,085	$ 319,149
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		$ 461,776	$ 420,762	$ 410,523
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		$ 560,728	$ 510,817	$ 498,492
Minimum capital required, Ratio (as a percent)		8.50%	8.50%	8.50%
Total capital to risk-weighted assets
Minimum capital required, Capital Amount		$ 692,665	$ 631,009	$ 615,784
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		$ 333,587	$ 328,085	$ 319,149
Minimum capital required, Ratio (as a percent)		4.00%	4.00%	4.00%
Forecast
Capital ratios
Capital conversion buffer common equity Tier 1 of risk-weighted assets (as a percent)	2.50%
South State Bank (the Bank)
Common equity Tier 1 to risk-weighted assets
Actual, Capital Amount		$ 790,497	$ 740,532	$ 720,522
Actual, Ratio (as a percent)		11.86%	12.33%	12.29%
Required to be considered well capitalized, Capital Amount		$ 428,647	$ 390,511	$ 380,999
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		$ 790,497	$ 740,532	$ 720,522
Actual, Ratio (as a percent)		11.86%	12.33%	12.29%
Required to be considered well capitalized, Capital Amount		$ 527,566	$ 480,629	$ 468,922
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		$ 831,429	$ 778,538	$ 760,322
Actual, Ratio (as a percent)		12.48%	12.96%	12.97%
Required to be considered well capitalized, Capital Amount		$ 659,457	$ 600,786	$ 586,153
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		$ 790,497	$ 740,532	$ 720,522
Actual, Ratio (as a percent)		9.42%	9.03%	9.04%
Required to be considered well capitalized, Capital Amount		$ 416,791	$ 409,818	$ 398,544
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		$ 337,972	$ 270,354	$ 263,769
Minimum capital required, Ratio (as a percent)		5.125%	4.50%	4.50%
Tier I capital to risk-weighted assets
Minimum capital required, Capital Amount		$ 395,674	$ 360,471	$ 351,692
Minimum capital required, Ratio (as a percent)		6.00%	6.00%	6.00%
Total capital to risk-weighted assets
Minimum capital required, Capital Amount		$ 527,566	$ 480,629	$ 468,922
Minimum capital required, Ratio (as a percent)		8.00%	8.00%	8.00%
Tier I capital to average assets (leverage ratio)
Minimum capital required, Capital Amount		$ 333,433	$ 327,854	$ 318,835
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		$ 461,620	$ 420,550	$ 410,307
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		$ 560,539	$ 510,668	$ 498,230
Minimum capital required, Ratio (as a percent)		8.50%	8.50%	8.50%
Total capital to risk-weighted assets
Minimum capital required, Capital Amount		$ 692,430	$ 630,825	$ 615,460
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		$ 333,433	$ 327,854	$ 318,835
Minimum capital required, Ratio (as a percent)		4.00%	4.00%	4.00%