Note 13 - Regulatory Matters - Summary of Actual Capital Amounts And Ratios (Details) $ in Thousands	Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Summit [Member]
CET1 (to risk weighted assets), amount	$ 381,890	$ 369,935
CET1 (to risk weighted assets), Actual Ratio	0.094	0.091
CET1 (to risk weighted assets), Minimum Required Capital, Amount	$ 285,018	$ 285,338
CET1 (to risk weighted assets), Minimum Required Capital, Ratio	0.07	0.07
Tier I Capital (to risk weighted assets), amount	$ 415,810	$ 403,855
Tier I Capital (to risk weighted assets), Actual Ratio	0.102	0.099
Tier I Capital (to risk weighted assets), Minimum Required Capital, Amount	$ 346,093	$ 346,481
Tier I Capital (to risk weighted assets), Minimum Required Capital, Ratio	0.085	0.085
Total Capital (to risk weighted assets), amount	$ 570,628	$ 556,590
Total Capital (to risk weighted assets), Actual Ratio	0.14	0.137
Total Capital (to risk weighted assets), Minimum Required Capital, Amount	$ 427,527	$ 428,006
Total Capital (to risk weighted assets), Minimum Required Capital, Ratio	0.105	0.105
Tier I Capital (to average assets), amount	$ 415,810	$ 403,855
Tier I Capital (to average assets), Actual Amount	0.09	0.087
Tier I Capital (to average assets), Minimum Required Capital, Amount	$ 184,166	$ 186,747
Tier I Capital (to average assets), Minimum Required Capital, Ratio	0.04	0.04
Summit Community [Member]
CET1 (to risk weighted assets), amount	$ 488,335	$ 475,785
CET1 (to risk weighted assets), Actual Ratio	0.12	0.117
CET1 (to risk weighted assets), Minimum Required Capital, Amount	$ 284,426	$ 284,873
CET1 (to risk weighted assets), Minimum Required Capital, Ratio	0.07	0.07
CET1 (to risk weighted assets), Minimum Required To Be Well Capitalized, Amount	$ 264,110	$ 264,525
CET1 (to risk weighted assets), Minimum Required To Be Well Capitalized, Ratio	0.065	0.065
Tier I Capital (to risk weighted assets), amount	$ 488,335	$ 475,785
Tier I Capital (to risk weighted assets), Actual Ratio	0.12	0.117
Tier I Capital (to risk weighted assets), Minimum Required Capital, Amount	$ 345,375	$ 345,917
Tier I Capital (to risk weighted assets), Minimum Required Capital, Ratio	0.085	0.085
Tier I Capital (to risk weighted assets), Minimum Required To Be Well Capitalized, Amount	$ 325,059	$ 325,569
Tier I Capital (to risk weighted assets), Minimum Required To Be Well Capitalized, Ratio	0.08	0.08
Total Capital (to risk weighted assets), amount	$ 539,145	$ 524,737
Total Capital (to risk weighted assets), Actual Ratio	0.133	0.129
Total Capital (to risk weighted assets), Minimum Required Capital, Amount	$ 426,640	$ 427,309
Total Capital (to risk weighted assets), Minimum Required Capital, Ratio	0.105	0.105
Total Capital (to risk weighted assets), Minimum Required To Be Well Capitalized, Amount	$ 406,324	$ 406,961
Total Capital (to risk weighted assets), Minimum Required To Be Well Capitalized, Ratio	0.10	0.10
Tier I Capital (to average assets), amount	$ 488,335	$ 475,785
Tier I Capital (to average assets), Actual Amount	0.106	0.102
Tier I Capital (to average assets), Minimum Required Capital, Amount	$ 183,982	$ 186,057
Tier I Capital (to average assets), Minimum Required Capital, Ratio	0.04	0.04
Tier I Capital (to average assets), Minimum Required To Be Well Capitalized, Amount	$ 229,977	$ 232,571
Tier I Capital (to average assets), Minimum Required To Be Well Capitalized, Ratio	0.05	0.05