Regulatory Matters - Summary of Company's and Equity Bank's Capital Amounts and Ratios (Detail) $ in Thousands	Jun. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital to risk weighted assets, To Be Well Capitalized Under Prompt Corrective Provisions, Actual Ratio	0.10
Tier 1 capital to risk weighted assets, To Be Well Capitalized Under Prompt Corrective Provisions, Actual Ratio	0.08
Common equity Tier 1 capital to risk weighted assets, To Be Well Capitalized Under Prompt Corrective Provisions, Actual Ratio	6.50%
Tier 1 leverage to average assets, To Be Well Capitalized Under Prompt Corrective Provisions, Actual Ratio	0.05
Equity Bancshares, Inc. [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital to risk weighted assets, Actual Amount	$ 595,887	$ 589,131
Total capital to risk weighted assets, Actual Ratio	0.1461	0.1548
Tier 1 capital to risk weighted assets, Actual Amount	$ 477,527	$ 470,659
Tier 1 capital to risk weighted assets, Actual Ratio	0.117	0.1236
Common equity Tier 1 capital to risk weighted assets, Actual Amount	$ 453,758	$ 447,064
Common equity Tier 1 capital to risk weighted assets, Actual Ratio	0.1112	0.1174
Tier 1 leverage to average assets, Actual Amount	$ 477,527	$ 470,659
Tier 1 leverage to average assets, Actual Ratio	0.0914	0.0946
Equity Bancshares, Inc. [Member] | Base III Phase-In [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital to risk weighted assets, Minimum Required for Capital Adequacy Purposes, Actual Amount	$ 428,401	$ 399,729
Total capital to risk weighted assets, Minimum Required for Capital Adequacy Purposes, Actual Ratio	0.105	0.105
Tier 1 capital to risk weighted assets, Minimum Required for Capital Adequacy Purposes, Actual Amount	$ 346,801	$ 323,590
Tier 1 capital to risk weighted assets, Minimum Required for Capital Adequacy Purposes, Actual Ratio	0.085	0.085
Common equity Tier 1 capital to risk weighted assets, Minimum Required for Capital Adequacy Purposes, Actual Amount	$ 285,601	$ 266,486
Common equity Tier 1 capital to risk weighted assets, Minimum Required for Capital Adequacy Purposes, Actual Ratio	7.00%	7.00%
Tier 1 leverage to average assets, Minimum Required for Capital Adequacy Purposes, Actual Amount	$ 208,903	$ 199,112
Tier 1 leverage to average assets, Minimum Required for Capital Adequacy Purposes, Actual Ratio	0.04	0.04
Equity Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital to risk weighted assets, Actual Amount	$ 571,710	$ 571,938
Total capital to risk weighted assets, Actual Ratio	0.1404	0.1505
Total capital to risk weighted assets, To Be Well Capitalized Under Prompt Corrective Provisions, Actual Amount	$ 407,437	$ 380,006
Total capital to risk weighted assets, To Be Well Capitalized Under Prompt Corrective Provisions, Actual Ratio	0.10	0.10
Tier 1 capital to risk weighted assets, Actual Amount	$ 526,777	$ 526,793
Tier 1 capital to risk weighted assets, Actual Ratio	0.1293	0.1386
Tier 1 capital to risk weighted assets, To Be Well Capitalized Under Prompt Corrective Provisions, Actual Amount	$ 325,877	$ 304,004
Tier 1 capital to risk weighted assets, To Be Well Capitalized Under Prompt Corrective Provisions, Actual Ratio	0.08	0.08
Common equity Tier 1 capital to risk weighted assets, Actual Amount	$ 526,777	$ 526,793
Common equity Tier 1 capital to risk weighted assets, Actual Ratio	0.1293	0.1386
Common equity Tier 1 capital to risk weighted assets, To Be Well Capitalized Under Prompt Corrective Provisions, Actual Amount	$ 264,775	$ 247,004
Common equity Tier 1 capital to risk weighted assets, To Be Well Capitalized Under Prompt Corrective Provisions, Actual Ratio	6.50%	6.50%
Tier 1 leverage to average assets, Actual Amount	$ 526,777	$ 526,793
Tier 1 leverage to average assets, Actual Ratio	0.1011	0.106
Tier 1 leverage to average assets, To Be Well Capitalized Under Prompt Corrective Provisions, Actual Amount	$ 260,591	$ 248,477
Tier 1 leverage to average assets, To Be Well Capitalized Under Prompt Corrective Provisions, Actual Ratio	0.05	0.05
Equity Bank [Member] | Base III Phase-In [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital to risk weighted assets, Minimum Required for Capital Adequacy Purposes, Actual Amount	$ 427,714	$ 399,006
Total capital to risk weighted assets, Minimum Required for Capital Adequacy Purposes, Actual Ratio	0.105	0.105
Tier 1 capital to risk weighted assets, Minimum Required for Capital Adequacy Purposes, Actual Amount	$ 346,245	$ 323,005
Tier 1 capital to risk weighted assets, Minimum Required for Capital Adequacy Purposes, Actual Ratio	0.085	0.085
Common equity Tier 1 capital to risk weighted assets, Minimum Required for Capital Adequacy Purposes, Actual Amount	$ 285,143	$ 266,004
Common equity Tier 1 capital to risk weighted assets, Minimum Required for Capital Adequacy Purposes, Actual Ratio	7.00%	7.00%
Tier 1 leverage to average assets, Minimum Required for Capital Adequacy Purposes, Actual Amount	$ 208,473	$ 198,782
Tier 1 leverage to average assets, Minimum Required for Capital Adequacy Purposes, Actual Ratio	0.04	0.04