Capital Ratios (Details) - USD ($) $ in Thousands	Jan. 01, 2019	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016
Common equity Tier 1 to risk-weighted assets
Actual, Capital Amount		$ 985,586	$ 788,544	$ 741,000
Actual, Ratio (as a percent)		11.96%	11.66%	11.23%
Minimum capital required, Ratio (as a percent)		4.50%
Required to be considered well capitalized, Capital Amount		$ 535,789	$ 439,755	$ 428,792
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		$ 1,056,506	$ 841,266	$ 793,116
Actual, Ratio (as a percent)		12.82%	12.43%	12.02%
Minimum capital required, Ratio (as a percent)		6.00%	4.00%
Required to be considered well capitalized, Capital Amount		$ 659,432	$ 541,237	$ 527,744
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		$ 1,100,757	$ 881,957	$ 834,102
Actual, Ratio (as a percent)		13.35%	13.04%	12.64%
Minimum capital required, Ratio (as a percent)		8.00%
Required to be considered well capitalized, Capital Amount		$ 824,290	$ 676,546	$ 659,681
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		$ 1,056,506	$ 841,266	$ 793,116
Actual, Ratio (as a percent)		10.12%	9.88%	9.51%
Minimum capital required, Ratio (as a percent)		4.00%
Required to be considered well capitalized, Capital Amount		$ 522,088	$ 425,765	$ 416,984
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		$ 473,967	$ 346,730	$ 338,086
Minimum capital required, Ratio (as a percent)		5.75%	5.125%	5.125%
Tier I capital to risk-weighted assets
Minimum capital required, Capital Amount		$ 597,610	$ 448,212	$ 437,038
Minimum capital required, Ratio (as a percent)		7.25%	6.625%	6.625%
Total capital to risk-weighted assets
Minimum capital required, Capital Amount		$ 762,468	$ 583,521	$ 568,974
Minimum capital required, Ratio (as a percent)		9.25%	8.625%	8.625%
Tier I capital to average assets (leverage ratio)
Minimum capital required, Capital Amount		$ 417,671	$ 340,612	$ 333,587
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		$ 577,003	$ 473,582	$ 461,776
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		$ 700,647	$ 575,064	$ 560,728
Minimum capital required, Ratio (as a percent)		8.50%	8.50%	8.50%
Total capital to risk-weighted assets
Minimum capital required, Capital Amount		$ 865,505	$ 710,374	$ 692,665
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		$ 417,671	$ 340,612	$ 333,587
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		$ 1,023,298	$ 815,823	$ 766,183
Actual, Ratio (as a percent)		12.41%	12.06%	11.62%
Required to be considered well capitalized, Capital Amount		$ 535,774	$ 439,627	$ 428,647
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		$ 1,023,298	$ 815,823	$ 766,183
Actual, Ratio (as a percent)		12.41%	12.06%	11.62%
Required to be considered well capitalized, Capital Amount		$ 659,414	$ 541,079	$ 527,566
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		$ 1,067,398	$ 856,388	$ 807,084
Actual, Ratio (as a percent)		12.95%	12.66%	12.24%
Required to be considered well capitalized, Capital Amount		$ 824,268	$ 676,349	$ 659,457
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		$ 1,023,298	$ 815,823	$ 766,183
Actual, Ratio (as a percent)		9.80%	9.58%	9.19%
Required to be considered well capitalized, Capital Amount		$ 521,921	$ 425,604	$ 416,791
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		$ 473,954	$ 346,629	$ 337,972
Minimum capital required, Ratio (as a percent)		5.75%	5.125%	5.125%
Tier I capital to risk-weighted assets
Minimum capital required, Capital Amount		$ 597,594	$ 448,081	$ 436,890
Minimum capital required, Ratio (as a percent)		7.25%	6.625%	6.625%
Total capital to risk-weighted assets
Minimum capital required, Capital Amount		$ 762,448	$ 583,351	$ 568,782
Minimum capital required, Ratio (as a percent)		9.25%	8.625%	8.625%
Tier I capital to average assets (leverage ratio)
Minimum capital required, Capital Amount		$ 417,537	$ 340,483	$ 333,433
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		$ 576,988	$ 473,444	$ 461,620
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		$ 700,628	$ 574,896	$ 560,539
Minimum capital required, Ratio (as a percent)		8.50%	8.50%	8.50%
Total capital to risk-weighted assets
Minimum capital required, Capital Amount		$ 865,481	$ 710,166	$ 692,430
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		$ 417,537	$ 340,483	$ 333,433
Minimum capital required, Ratio (as a percent)		4.00%	4.00%	4.00%