Regulatory Matters - Summary of Company's and Equity Bank's Capital Amounts and Ratios (Detail) $ in Thousands	Dec. 31, 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	$ 720,736	$ 589,131
Total capital to risk weighted assets, Actual Ratio	0.1807	0.1548
Tier 1 capital to risk weighted assets, Actual Amount	$ 602,496	$ 470,659
Tier 1 capital to risk weighted assets, Actual Ratio	0.1511	0.1236
Common equity Tier 1 capital to risk weighted assets, Actual Amount	$ 578,550	$ 447,064
Common equity Tier 1 capital to risk weighted assets, Actual Ratio	0.1451	0.1174
Tier 1 leverage to average assets, Actual Amount	$ 602,496	$ 470,659
Tier 1 leverage to average assets, Actual Ratio	0.1167	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	$ 418,716	$ 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	$ 338,961	$ 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	$ 279,144	$ 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	$ 206,442	$ 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	$ 607,579	$ 571,938
Total capital to risk weighted assets, Actual Ratio	0.1527	0.1505
Total capital to risk weighted assets, To Be Well Capitalized Under Prompt Corrective Provisions, Actual Amount	$ 397,830	$ 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	$ 562,870	$ 526,793
Tier 1 capital to risk weighted assets, Actual Ratio	0.1415	0.1386
Tier 1 capital to risk weighted assets, To Be Well Capitalized Under Prompt Corrective Provisions, Actual Amount	$ 318,264	$ 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	$ 562,870	$ 526,793
Common equity Tier 1 capital to risk weighted assets, Actual Ratio	0.1415	0.1386
Common equity Tier 1 capital to risk weighted assets, To Be Well Capitalized Under Prompt Corrective Provisions, Actual Amount	$ 258,590	$ 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	$ 562,870	$ 526,793
Tier 1 leverage to average assets, Actual Ratio	0.1093	0.106
Tier 1 leverage to average assets, To Be Well Capitalized Under Prompt Corrective Provisions, Actual Amount	$ 257,500	$ 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	$ 417,722	$ 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	$ 338,156	$ 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	$ 278,481	$ 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	$ 206,000	$ 198,782
Tier 1 leverage to average assets, Minimum Required for Capital Adequacy Purposes, Actual Ratio	0.04	0.04