Regulatory Capital - Summary of Company's and Wilson Banks Actual Capital Amounts and Ratios (Details) $ in Thousands		Sep. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital to risk weighted assets actual amount		$ 597,992	$ 560,757
Total capital to risk weighted assets actual ratio		0.145	0.145
Total capital to risk weighted assets regulatory minimum capital requirement amount		$ 330,949	$ 308,449
Total capital to risk weighted assets regulatory minimum capital requirement ratio		0.08	0.08
Total capital to risk weighted assets well capitalized amount	[1]	$ 413,686	$ 385,562
Total capital to risk weighted assets regulatory minimum capital requirement well capitalized ratio	[2]	0.10	0.10
Tier 1 capital to risk weighted assets actual amount		$ 547,366	$ 512,762
Tier 1 capital to risk weighted assets actual ratio		0.132	0.133
Tier 1 capital to risk weighted assets regulatory minimum capital requirement amount		$ 248,212	$ 231,337
Tier 1 capital to risk weighted assets regulatory minimum capital requirement ratio		0.06	0.06
Tier 1 capital to risk well capitalized amount	[1]	$ 248,212	$ 231,337
Tier 1 capital to risk weighted assets regulatory well capitalized ratio	[2]	0.06	0.06
Common equity Tier 1 capital to risk weighted assets actual amount		$ 547,205	$ 512,693
Common equity Tier 1 capital to risk weighted assets actual ratio		0.132	0.133
Common equity Tier 1 capital to risk weighted assets regulatory minimum capital requirement amount		$ 186,159	$ 173,503
Common equity Tier 1 capital to risk weighted assets regulatory minimum capital requirement ratio		0.045	0.045
Tier 1 capital to average assets actual amount		$ 547,366	$ 512,762
Tier 1 capital to average assets actual ratio		0.105	0.106
Tier 1 capital to average assets regulatory minimum capital requirement amount		$ 208,809	$ 193,564
Tier 1 capital to average assets regulatory minimum capital requirement ratio (as a percent)		0.04	0.04
Wilson Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital to risk weighted assets actual amount		$ 592,688	$ 559,224
Total capital to risk weighted assets actual ratio		0.143	0.145
Total capital to risk weighted assets regulatory minimum capital requirement amount		$ 330,829	$ 308,333
Total capital to risk weighted assets regulatory minimum capital requirement ratio		0.08	0.08
Total capital to risk weighted assets well capitalized amount	[1]	$ 413,536	$ 385,417
Total capital to risk weighted assets regulatory minimum capital requirement well capitalized ratio	[2]	0.10	0.10
Tier 1 capital to risk weighted assets actual amount		$ 542,062	$ 511,229
Tier 1 capital to risk weighted assets actual ratio		0.131	0.133
Tier 1 capital to risk weighted assets regulatory minimum capital requirement amount		$ 248,121	$ 231,250
Tier 1 capital to risk weighted assets regulatory minimum capital requirement ratio		0.06	0.06
Tier 1 capital to risk well capitalized amount	[1]	$ 330,828	$ 308,334
Tier 1 capital to risk weighted assets regulatory well capitalized ratio	[2]	0.08	0.08
Common equity Tier 1 capital to risk weighted assets actual amount		$ 541,901	$ 511,160
Common equity Tier 1 capital to risk weighted assets actual ratio		0.131	0.133
Common equity Tier 1 capital to risk weighted assets regulatory minimum capital requirement amount		$ 186,091	$ 173,438
Common equity Tier 1 capital to risk weighted assets regulatory minimum capital requirement ratio		0.045	0.045
Common equity Tier 1 capital to risk weighted assets regulatory well capitalized	[1]	$ 268,798	$ 250,521
Common equity Tier 1 capital to risk weighted assets well capitalized ratio	[2]	0.065	0.065
Tier 1 capital to average assets actual amount		$ 542,062	$ 511,229
Tier 1 capital to average assets actual ratio		0.104	0.106
Tier 1 capital to average assets regulatory minimum capital requirement amount		$ 208,740	$ 193,492
Tier 1 capital to average assets regulatory minimum capital requirement ratio (as a percent)		0.04	0.04
Tier 1 capital to average assets well capitalized	[1]	$ 260,925	$ 241,865
Tier 1 capital to average assets well capitalized ratio	[2]	0.05	0.05

[1] Well-capitalized minimum Common equity Tier 1 capital to risk weighted assets and Tier 1 capital to average assets are not formally defined under applicable regulations for bank holding companies.

[2] Ratios for Wilson Bank are those under applicable FDIC regulations for prompt corrective action.