Capital Ratios (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020	Jan. 01, 2020	Jan. 01, 2019
Capital ratios
Capital conversion buffer common equity Tier 1 of risk-weighted assets (as a percent)						2.50%
Additional allowance for credit losses for loans	$ 300,396	$ 301,807	$ 406,460	$ 457,309
Deferred tax assets	136,078	64,964
Additional reserve for unfunded commitments	30,400
Retained earnings	$ 1,064,064	997,657
Phasing out percentage	25.00%
Common equity Tier 1 to risk-weighted assets
Actual, Capital Amount	$ 3,472,948	$ 3,201,644
Actual, Ratio (as a percent)	11.37%	11.75%
Minimum capital required, Capital Amount	$ 2,138,431	$ 1,906,831
Minimum capital required, Ratio (as a percent)	7.00%	7.00%
Required to be considered well capitalized, Capital Amount	$ 1,985,686	$ 1,770,629
Required to be considered well capitalized, Ratio (as a percent)	6.50%	6.50%
Tier I capital to risk-weighted assets
Actual, Capital Amount	$ 3,472,948	$ 3,201,644
Actual, Ratio (as a percent)	11.37	11.75
Minimum capital required, Capital Amount	$ 2,596,666	$ 2,315,438
Minimum capital required, Ratio (as a percent)	8.50	8.50
Required to be considered well capitalized, Capital Amount	$ 2,443,921	$ 2,179,236
Required to be considered well capitalized, Ratio (as a percent)	8.00	8.00
Total capital to risk-weighted assets
Actual, Capital Amount	$ 4,064,615	$ 3,692,674
Actual, Ratio (as a percent)	13.31	13.56
Minimum capital required, Capital Amount	$ 3,207,647	$ 2,860,247
Minimum capital required, Ratio (as a percent)	10.50	10.50
Required to be considered well capitalized, Capital Amount	$ 3,054,902	$ 2,724,045
Required to be considered well capitalized, Ratio (as a percent)	10.00	10.00
Tier I capital to average assets (leverage ratio)
Actual, Capital Amount	$ 3,472,948	$ 3,201,644
Actual, Ratio (as a percent)	8.45	8.05
Minimum capital required, Capital Amount	$ 1,643,247	$ 1,590,045
Minimum capital required, Ratio (as a percent)	4.00	4.00
Required to be considered well capitalized, Capital Amount	$ 2,054,058	$ 1,987,556
Required to be considered well capitalized, Ratio (as a percent)	5.00	5.00
ASU 2016-13
Capital ratios
Additional allowance for credit losses for loans					$ 54,400
Deferred tax assets					12,600
Retained earnings					(44,800)
ASU 2016-13 | Adjustments
Capital ratios
Additional reserve for unfunded commitments					$ 6,400
SouthState Bank (the Bank)
Common equity Tier 1 to risk-weighted assets
Actual, Capital Amount	$ 3,773,163	$ 3,431,069
Actual, Ratio (as a percent)	12.37%	12.62%
Minimum capital required, Capital Amount	$ 2,134,908	$ 1,902,954
Minimum capital required, Ratio (as a percent)	7.00%	7.00%
Required to be considered well capitalized, Capital Amount	$ 1,982,415	$ 1,767,029
Required to be considered well capitalized, Ratio (as a percent)	6.50%	6.50%
Tier I capital to risk-weighted assets
Actual, Capital Amount	$ 3,773,163	$ 3,431,069
Actual, Ratio (as a percent)	12.37	12.62
Minimum capital required, Capital Amount	$ 2,592,389	$ 2,310,730
Minimum capital required, Ratio (as a percent)	8.50	8.50
Required to be considered well capitalized, Capital Amount	$ 2,439,895	$ 2,174,804
Required to be considered well capitalized, Ratio (as a percent)	8.00	8.00
Total capital to risk-weighted assets
Actual, Capital Amount	$ 3,961,830	$ 3,594,099
Actual, Ratio (as a percent)	12.99	13.22
Minimum capital required, Capital Amount	$ 3,202,362	$ 2,854,431
Minimum capital required, Ratio (as a percent)	10.50	10.50
Required to be considered well capitalized, Capital Amount	$ 3,049,869	$ 2,718,505
Required to be considered well capitalized, Ratio (as a percent)	10.00	10.00
Tier I capital to average assets (leverage ratio)
Actual, Capital Amount	$ 3,773,163	$ 3,431,069
Actual, Ratio (as a percent)	9.19	8.65
Minimum capital required, Capital Amount	$ 1,642,556	$ 1,587,212
Minimum capital required, Ratio (as a percent)	4.00	4.00
Required to be considered well capitalized, Capital Amount	$ 2,053,196	$ 1,984,015
Required to be considered well capitalized, Ratio (as a percent)	5.00	5.00
Minimum
Common equity Tier 1 to risk-weighted assets
Actual, Ratio (as a percent)	4.50%
Tier I capital to risk-weighted assets
Actual, Ratio (as a percent)	6
Total capital to risk-weighted assets
Actual, Ratio (as a percent)	4
Tier I capital to average assets (leverage ratio)
Actual, Ratio (as a percent)	8