Capital Ratios (Details) - USD ($) $ in Thousands	Jan. 01, 2019	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
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		$ 693,121
Actual, Ratio (as a percent)		11.82%
Minimum capital required, Ratio (as a percent)		4.50%
Required to be considered well capitalized, Capital Amount		$ 381,200
Required to be considered well capitalized, Ratio (as a percent)		6.50%
Tier I capital to risk-weighted assets
Actual, Capital Amount		$ 743,805	$ 713,371	$ 694,095
Actual, Ratio (as a percent)		12.68%	13.62%	13.29%
Minimum capital required, Capital Amount			$ 209,491	$ 208,900
Minimum capital required, Ratio (as a percent)		6.00%	4.00%	8.00%
Required to be considered well capitalized, Capital Amount		$ 469,169
Required to be considered well capitalized, Ratio (as a percent)		8.00%
Total capital to risk-weighted assets
Actual, Capital Amount		$ 783,605	$ 755,484	$ 737,243
Actual, Ratio (as a percent)		13.36%	14.43%	14.12%
Minimum capital required, Capital Amount			$ 418,982	$ 417,800
Minimum capital required, Ratio (as a percent)		8.00%	8.00%	4.00%
Required to be considered well capitalized, Capital Amount		$ 586,461
Required to be considered well capitalized, Ratio (as a percent)		10.00%
Tier I capital to average assets (leverage ratio)
Actual, Capital Amount		$ 743,805	$ 713,371	$ 694,095
Actual, Ratio (as a percent)		9.32%	9.47%	9.16%
Minimum capital required, Capital Amount			$ 301,363	$ 303,233
Minimum capital required, Ratio (as a percent)		4.00%	4.00%	4.00%
Required to be considered well capitalized, Capital Amount		$ 398,937
Required to be considered well capitalized, Ratio (as a percent)		5.00%
Phase-In Schedule
Common equity Tier 1 to risk-weighted assets
Minimum capital required, Capital Amount		$ 263,907
Minimum capital required, Ratio (as a percent)		4.50%
Tier I capital to risk-weighted assets
Minimum capital required, Capital Amount		$ 351,877
Minimum capital required, Ratio (as a percent)		6.00%
Total capital to risk-weighted assets
Minimum capital required, Capital Amount		$ 469,169
Minimum capital required, Ratio (as a percent)		8.00%
Tier I capital to average assets (leverage ratio)
Minimum capital required, Capital Amount		$ 319,149
Minimum capital required, Ratio (as a percent)		4.00%
Fully Phased-In
Common equity Tier 1 to risk-weighted assets
Minimum capital required, Capital Amount		$ 410,523
Minimum capital required, Ratio (as a percent)		7.00%
Tier I capital to risk-weighted assets
Minimum capital required, Capital Amount		$ 498,492
Minimum capital required, Ratio (as a percent)		8.50%
Total capital to risk-weighted assets
Minimum capital required, Capital Amount		$ 615,784
Minimum capital required, Ratio (as a percent)		10.50%
Tier I capital to average assets (leverage ratio)
Minimum capital required, Capital Amount		$ 319,149
Minimum capital required, Ratio (as a percent)		4.00%
South State Bank (the Bank)
Common equity Tier 1 to risk-weighted assets
Actual, Capital Amount		$ 720,522
Actual, Ratio (as a percent)		12.29%
Required to be considered well capitalized, Capital Amount		$ 380,999
Required to be considered well capitalized, Ratio (as a percent)		6.50%
Tier I capital to risk-weighted assets
Actual, Capital Amount		$ 720,522	$ 700,280	$ 684,033
Actual, Ratio (as a percent)		12.29%	13.37%	13.09%
Minimum capital required, Capital Amount			$ 209,438	$ 208,971
Minimum capital required, Ratio (as a percent)			4.00%	8.00%
Required to be considered well capitalized, Capital Amount		$ 468,922	$ 314,158	$ 313,456
Required to be considered well capitalized, Ratio (as a percent)		8.00%	6.00%	6.00%
Total capital to risk-weighted assets
Actual, Capital Amount		$ 760,322	$ 742,393	$ 727,079
Actual, Ratio (as a percent)		12.97%	14.18%	13.92%
Minimum capital required, Capital Amount			$ 418,877	$ 417,941
Minimum capital required, Ratio (as a percent)			8.00%	4.00%
Required to be considered well capitalized, Capital Amount		$ 586,153	$ 523,596	$ 522,426
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		$ 720,522	$ 700,280	$ 684,033
Actual, Ratio (as a percent)		9.04%	9.30%	9.03%
Minimum capital required, Capital Amount			$ 301,162	$ 303,066
Minimum capital required, Ratio (as a percent)			4.00%	4.00%
Required to be considered well capitalized, Capital Amount		$ 398,544	$ 376,452	$ 378,833
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		$ 263,769
Minimum capital required, Ratio (as a percent)		4.50%
Tier I capital to risk-weighted assets
Minimum capital required, Capital Amount		$ 351,692
Minimum capital required, Ratio (as a percent)		6.00%
Total capital to risk-weighted assets
Minimum capital required, Capital Amount		$ 468,922
Minimum capital required, Ratio (as a percent)		8.00%
Tier I capital to average assets (leverage ratio)
Minimum capital required, Capital Amount		$ 318,835
Minimum capital required, Ratio (as a percent)		4.00%
South State Bank (the Bank) | Fully Phased-In
Common equity Tier 1 to risk-weighted assets
Minimum capital required, Capital Amount		$ 410,307
Minimum capital required, Ratio (as a percent)		7.00%
Tier I capital to risk-weighted assets
Minimum capital required, Capital Amount		$ 498,230
Minimum capital required, Ratio (as a percent)		8.50%
Total capital to risk-weighted assets
Minimum capital required, Capital Amount		$ 615,460
Minimum capital required, Ratio (as a percent)		10.50%
Tier I capital to average assets (leverage ratio)
Minimum capital required, Capital Amount		$ 318,835
Minimum capital required, Ratio (as a percent)		4.00%