Regulatory Matters - Summary of Capital Ratios (Detail) $ in Thousands	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Company
Total capital (to risk-weighted assets)
Total capital (to risk-weighted assets)	$ 903,415	$ 783,107
Total capital (to risk-weighted assets), For capital adequacy purposes	654,978	640,632
Tier 1 capital (to risk-weighted assets)
Tier 1 capital (to risk-weighted assets)	695,634	623,644
Tier 1 capital (to risk-weighted assets), For capital adequacy purposes	530,220	518,607
Common equity Tier 1 capital (to risk-weighted assets)
Common equity Tier 1 capital (to risk-weighted assets)	665,634	593,644
Common equity Tier 1 capital (to risk-weighted assets), For capital adequacy purposes	436,652	427,088
Tier 1 capital (to average assets)
Tier 1 capital (to average assets)	695,634	623,644
Tier 1 capital (to average assets), For capital adequacy purposes	$ 326,813	$ 298,096
Risk Based Ratios [Abstract]
Total capital (to risk-weighted assets), ratio	0.1448	0.1284
Tier 1 capital (to risk-weighted assets), ratio	0.1115	0.1022
Common equity Tier 1 capital (to risk-weighted assets), ratio	0.1067	0.0973
Tier 1 capital (to average assets), ratio	0.0851	0.0837
Total capital (to risk-weighted assets), For capital adequacy purposes , ratio	10.5	10.5
Tier 1 capital (to risk-weighted assets), For capital adequacy purposes, ratio	8.5	8.5
Common equity Tier 1 capital (to risk-weighted assets), For capital adequacy purposes, ratio	700.00%	700.00%
Tier 1 capital (to average assets), For capital adequacy purposes, ratio	4	4
Lakeland
Total capital (to risk-weighted assets)
Total capital (to risk-weighted assets)	$ 852,339	$ 745,276
Total capital (to risk-weighted assets), For capital adequacy purposes	654,692	640,416
Total capital (to risk - weighted assets), To be well capitalized under prompt corrective action provisions	623,516	609,920
Tier 1 capital (to risk-weighted assets)
Tier 1 capital (to risk-weighted assets)	792,363	672,832
Tier 1 capital (to risk-weighted assets), For capital adequacy purposes	529,989	518,432
Tier 1 capital (to risk-weighted assets), To be well capitalized under prompt corrective action provisions	498,813	487,936
Common equity Tier 1 capital (to risk-weighted assets)
Common equity Tier 1 capital (to risk-weighted assets)	792,363	672,832
Common equity Tier 1 capital (to risk-weighted assets), For capital adequacy purposes	436,461	426,944
Common equity Tier 1 capital (to risk-weighted assets), To be well capitalized under prompt corrective action provisions	405,285	396,448
Tier 1 capital (to average assets)
Tier 1 capital (to average assets)	792,363	672,832
Tier 1 capital (to average assets), For capital adequacy purposes	326,734	297,748
Tier 1 capital (to average assets), To be well capitalized under prompt corrective action provisions	$ 408,418	$ 372,185
Risk Based Ratios [Abstract]
Total capital (to risk-weighted assets), ratio	0.1367	0.1222
Tier 1 capital (to risk-weighted assets), ratio	0.1271	0.1103
Common equity Tier 1 capital (to risk-weighted assets), ratio	0.1271	0.1103
Tier 1 capital (to average assets), ratio	0.0970	0.0904
Total capital (to risk-weighted assets), For capital adequacy purposes , ratio	0.1050	0.1050
Tier 1 capital (to risk-weighted assets), For capital adequacy purposes, ratio	0.0850	0.0850
Common equity Tier 1 capital (to risk-weighted assets), For capital adequacy purposes, ratio	7.00%	7.00%
Tier 1 capital (to average assets), For capital adequacy purposes, ratio	0.0400	0.0400
Total capital (to risk - weighted assets), To be well capitalized under prompt corrective action provisions, ratio	10	10
Tier 1 capital (to risk-weighted assets), To be well capitalized under prompt corrective action provisions, ratio	8	8
Common equity Tier 1 capital (to risk-weighted assets), To be well capitalized under prompt corrective action provisions, ratio	650.00%	650.00%
Tier 1 capital (to average assets), To be well capitalized under prompt corrective action provisions, ratio	5	5

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