Capital Ratios (Details) - USD ($) $ in Thousands	Jan. 01, 2019	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
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		$ 720,309	$ 711,577	$ 670,750
Actual, Ratio (as a percent)		11.56%	11.84%	12.26%
Minimum capital required, Ratio (as a percent)		4.50%
Required to be considered well capitalized, Capital Amount		$ 404,867	$ 390,624	$ 355,908
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		$ 772,046	$ 763,590	$ 721,069
Actual, Ratio (as a percent)		12.39%	12.71%	13.18%
Minimum capital required, Ratio (as a percent)		6.00%	4.00%
Required to be considered well capitalized, Capital Amount		$ 498,298	$ 480,768	$ 438,041
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		$ 811,352	$ 801,745	$ 759,534
Actual, Ratio (as a percent)		13.03%	13.34%	13.89%
Minimum capital required, Ratio (as a percent)		8.00%
Required to be considered well capitalized, Capital Amount		$ 622,873	$ 600,961	$ 547,551
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		$ 772,046	$ 763,590	$ 721,069
Actual, Ratio (as a percent)		9.41%	9.31%	9.53%
Minimum capital required, Ratio (as a percent)		4.00%
Required to be considered well capitalized, Capital Amount		$ 410,074	$ 410,107	$ 378,197
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		$ 319,222	$ 270,432	$ 246,398
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		$ 373,724	$ 360,576	$ 328,531
Minimum capital required, Ratio (as a percent)		6.00%	6.00%	6.00%
Total capital to risk-weighted assets
Minimum capital required, Capital Amount		$ 498,298	$ 480,768	$ 438,041
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		$ 328,059	$ 328,085	$ 302,558
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		$ 436,011	$ 420,762	$ 383,286
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		$ 529,442	$ 510,817	$ 465,418
Minimum capital required, Ratio (as a percent)		8.50%	8.50%	8.50%
Total capital to risk-weighted assets
Minimum capital required, Capital Amount		$ 654,017	$ 631,009	$ 574,928
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		$ 328,059	$ 328,085	$ 302,558
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		$ 749,214	$ 740,532	$ 707,542
Actual, Ratio (as a percent)		12.03%	12.33%	12.93%
Required to be considered well capitalized, Capital Amount		$ 404,826	$ 390,511	$ 355,748
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		$ 749,214	$ 740,532	$ 707,542
Actual, Ratio (as a percent)		12.03%	12.33%	12.93%
Required to be considered well capitalized, Capital Amount		$ 498,247	$ 480,629	$ 437,843
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		$ 788,417	$ 778,538	$ 746,008
Actual, Ratio (as a percent)		12.66%	12.96%	13.63%
Required to be considered well capitalized, Capital Amount		$ 622,809	$ 600,786	$ 547,304
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		$ 749,214	$ 740,532	$ 707,542
Actual, Ratio (as a percent)		9.14%	9.03%	9.36%
Required to be considered well capitalized, Capital Amount		$ 409,803	$ 409,818	$ 377,989
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		$ 319,190	$ 270,354	$ 246,287
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		$ 373,686	$ 360,471	$ 328,383
Minimum capital required, Ratio (as a percent)		6.00%	6.00%	6.00%
Total capital to risk-weighted assets
Minimum capital required, Capital Amount		$ 498,247	$ 480,629	$ 437,483
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		$ 327,842	$ 327,854	$ 302,391
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		$ 435,967	$ 420,550	$ 383,113
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		$ 529,388	$ 510,668	$ 465,209
Minimum capital required, Ratio (as a percent)		8.50%	8.50%	8.50%
Total capital to risk-weighted assets
Minimum capital required, Capital Amount		$ 653,950	$ 630,825	$ 574,669
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		$ 327,842	$ 327,854	$ 302,391
Minimum capital required, Ratio (as a percent)		4.00%	4.00%	4.00%