Note 18 - Regulatory Capital Requirements and Restrictions on Dividends - Capital Requirements (Details) $ in Thousands			12 Months Ended
	May 19, 2022 shares	Feb. 13, 2020 shares	Dec. 31, 2023 USD ($) security shares	Dec. 31, 2022 USD ($) shares
Total risk-based capital, actual, amount			$ 1,171,047	$ 1,055,177
Total risk-based capital, actual, ratio			0.1429	0.1428
Total risk-based capital for capital adequacy purposes, amount			$ 655,461	$ 591,132
Total risk-based capital for capital adequacy purposes, ratio			0.0800	0.0800
Total risk-based capital for capital adequacy purposes with capital conservation buffer, amount			$ 860,293	$ 775,861
Total risk-based capital for capital adequacy purposes with capital conservation buffer, ratio			0.1050	0.1050
Total risk-based capital to be well capitalized under prompt corrective action provisions, amount			$ 819,327	$ 738,915
Total risk-based capital to be well capitalized under prompt corrective action provisions, ratio			0.1000	0.1000
Tier 1 risk-based capital, actual, amount			$ 841,052	$ 734,977
Tier 1 risk-based capital, actual, ratio			0.1027	0.0995
Tier 1 risk-based capital for capital adequacy purposes, amount			$ 491,596	$ 443,349
Tier 1 risk-based capital for capital adequacy purposes, ratio			0.0600	0.0600
Tier 1 risk-based capital for capital adequacy purposes with capital conservation buffer, amount			$ 696,428	$ 628,078
Tier 1 risk-based capital for capital adequacy purposes with capital conservation buffer, ratio			0.0850	0.0850
Tier 1 risk-based capital to be well capitalized under prompt corrective action provisions, amount			$ 655,461	$ 591,132
Tier 1 risk-based capital to be well capitalized under prompt corrective action provisions, ratio			0.0800	0.0800
Tier 1 leverage, actual, amount			$ 841,052	$ 734,977
Tier 1 leverage, actual, ratio			0.1003	0.0961
Tier 1 leverage for capital adequacy purposes, amount			$ 335,420	$ 305,959
Tier 1 leverage for capital adequacy purposes, ratio			0.0400	0.0400
Tier 1 leverage for capital adequacy purposes with capital conservation buffer, amount			$ 335,420	$ 305,959
Tier 1 leverage for capital adequacy purposes with capital conservation buffer, ratio			0.0400	0.0400
Tier 1 leverage to be well capitalized under prompt corrective action provisions, amount			$ 419,275	$ 382,449
Tier 1 leverage to be well capitalized under prompt corrective action provisions, ratio			0.0500	0.0500
Common equity Tier 1, actual, amount			$ 792,321	$ 686,375
Common equity Tier 1, actual ratio			0.0967	0.0929
Common equity Tier 1 for capital adequacy purposes, amount			$ 368,697	$ 332,512
Common equity Tier 1 for capital adequacy purposes, ratio			0.045%	0.045%
Common equity Tier 1 for capital adequacy purposes with capital conservation buffer, amount			$ 573,529	$ 517,241
Common equity Tier 1 for capital adequacy purposes with capital conservation buffer, ratio			7.00%	0.07%
Common equity Tier 1 to be well capitalized under prompt corrective action provisions, amount			$ 532,562	$ 480,295
Common equity Tier 1 to be well capitalized under prompt corrective action provisions, ratio			6.50%	0.065%
The number of junior subordinated private placement debentures issued | security			4
The number of junior subordinated private placement debentures assumed | security			4
Percentage of outstanding shares under share repurchase program	10.00%	5.00%
Shares repurchased | shares			175,000	970,000
Number of shares remaining for repurchase | shares			760,915
Maximum
Shares repurchased authorized | shares	1,500,000	800,000
QCBT
Total risk-based capital, actual, amount			$ 300,413	$ 275,337
Total risk-based capital, actual, ratio			0.1267	0.1307
Total risk-based capital for capital adequacy purposes, amount			$ 189,707	$ 168,588
Total risk-based capital for capital adequacy purposes, ratio			0.0800	0.0800
Total risk-based capital for capital adequacy purposes with capital conservation buffer, amount			$ 248,990	$ 221,272
Total risk-based capital for capital adequacy purposes with capital conservation buffer, ratio			0.1050	0.1050
Total risk-based capital to be well capitalized under prompt corrective action provisions, amount			$ 237,133	$ 210,735
Total risk-based capital to be well capitalized under prompt corrective action provisions, ratio			0.1000	0.1000
Tier 1 risk-based capital, actual, amount			$ 270,744	$ 248,978
Tier 1 risk-based capital, actual, ratio			0.1142	0.1181
Tier 1 risk-based capital for capital adequacy purposes, amount			$ 142,280	$ 126,441
Tier 1 risk-based capital for capital adequacy purposes, ratio			0.0600	0.0600
Tier 1 risk-based capital for capital adequacy purposes with capital conservation buffer, amount			$ 201,563	$ 179,125
Tier 1 risk-based capital for capital adequacy purposes with capital conservation buffer, ratio			0.0850	0.0850
Tier 1 risk-based capital to be well capitalized under prompt corrective action provisions, amount			$ 189,707	$ 168,588
Tier 1 risk-based capital to be well capitalized under prompt corrective action provisions, ratio			0.0800	0.0800
Tier 1 leverage, actual, amount			$ 270,744	$ 248,978
Tier 1 leverage, actual, ratio			0.1123	0.1101
Tier 1 leverage for capital adequacy purposes, amount			$ 96,425	$ 90,419
Tier 1 leverage for capital adequacy purposes, ratio			0.0400	0.0400
Tier 1 leverage for capital adequacy purposes with capital conservation buffer, amount			$ 96,425	$ 90,419
Tier 1 leverage for capital adequacy purposes with capital conservation buffer, ratio			0.0400	0.0400
Tier 1 leverage to be well capitalized under prompt corrective action provisions, amount			$ 120,531	$ 133,023
Tier 1 leverage to be well capitalized under prompt corrective action provisions, ratio			0.0500	0.0500
Common equity Tier 1, actual, amount			$ 270,744	$ 248,978
Common equity Tier 1, actual ratio			0.1142	0.1181
Common equity Tier 1 for capital adequacy purposes, amount			$ 106,710	$ 94,831
Common equity Tier 1 for capital adequacy purposes, ratio			0.045%	0.045%
Common equity Tier 1 for capital adequacy purposes with capital conservation buffer, amount			$ 165,993	$ 147,514
Common equity Tier 1 for capital adequacy purposes with capital conservation buffer, ratio			7.00%	0.07%
Common equity Tier 1 to be well capitalized under prompt corrective action provisions, amount			$ 154,137	$ 136,978
Common equity Tier 1 to be well capitalized under prompt corrective action provisions, ratio			6.50%	0.065%
CRBT
Total risk-based capital, actual, amount			$ 381,514	$ 308,153
Total risk-based capital, actual, ratio			0.1560	0.1484
Total risk-based capital for capital adequacy purposes, amount			$ 195,687	$ 166,168
Total risk-based capital for capital adequacy purposes, ratio			0.0800	0.0800
Total risk-based capital for capital adequacy purposes with capital conservation buffer, amount			$ 256,840	$ 218,096
Total risk-based capital for capital adequacy purposes with capital conservation buffer, ratio			0.1050	0.1050
Total risk-based capital to be well capitalized under prompt corrective action provisions, amount			$ 244,609	$ 207,711
Total risk-based capital to be well capitalized under prompt corrective action provisions, ratio			0.1000	0.1000
Tier 1 risk-based capital, actual, amount			$ 354,940	$ 282,258
Tier 1 risk-based capital, actual, ratio			0.1451	0.1359
Tier 1 risk-based capital for capital adequacy purposes, amount			$ 146,766	$ 124,626
Tier 1 risk-based capital for capital adequacy purposes, ratio			0.0600	0.0600
Tier 1 risk-based capital for capital adequacy purposes with capital conservation buffer, amount			$ 207,918	$ 176,554
Tier 1 risk-based capital for capital adequacy purposes with capital conservation buffer, ratio			0.0850	0.0850
Tier 1 risk-based capital to be well capitalized under prompt corrective action provisions, amount			$ 195,687	$ 166,168
Tier 1 risk-based capital to be well capitalized under prompt corrective action provisions, ratio			0.0800	0.0800
Tier 1 leverage, actual, amount			$ 354,940	$ 282,258
Tier 1 leverage, actual, ratio			0.1477	0.1317
Tier 1 leverage for capital adequacy purposes, amount			$ 96,093	$ 85,707
Tier 1 leverage for capital adequacy purposes, ratio			0.0400	0.0400
Tier 1 leverage for capital adequacy purposes with capital conservation buffer, amount			$ 96,093	$ 85,707
Tier 1 leverage for capital adequacy purposes with capital conservation buffer, ratio			0.0400	0.0400
Tier 1 leverage to be well capitalized under prompt corrective action provisions, amount			$ 120,116	$ 107,134
Tier 1 leverage to be well capitalized under prompt corrective action provisions, ratio			0.0500	0.0500
Common equity Tier 1, actual, amount			$ 354,940	$ 282,258
Common equity Tier 1, actual ratio			0.1451	0.1359
Common equity Tier 1 for capital adequacy purposes, amount			$ 110,074	$ 93,470
Common equity Tier 1 for capital adequacy purposes, ratio			0.045%	0.045%
Common equity Tier 1 for capital adequacy purposes with capital conservation buffer, amount			$ 171,227	$ 145,397
Common equity Tier 1 for capital adequacy purposes with capital conservation buffer, ratio			7.00%	0.07%
Common equity Tier 1 to be well capitalized under prompt corrective action provisions, amount			$ 158,996	$ 135,012
Common equity Tier 1 to be well capitalized under prompt corrective action provisions, ratio			6.50%	0.065%
CSB
Total risk-based capital, actual, amount			$ 171,747	$ 142,974
Total risk-based capital, actual, ratio			0.1322	0.1204
Total risk-based capital for capital adequacy purposes, amount			$ 103,903	$ 94,981
Total risk-based capital for capital adequacy purposes, ratio			0.0800	0.0800
Total risk-based capital for capital adequacy purposes with capital conservation buffer, amount			$ 136,372	$ 124,662
Total risk-based capital for capital adequacy purposes with capital conservation buffer, ratio			0.1050	0.1050
Total risk-based capital to be well capitalized under prompt corrective action provisions, amount			$ 129,878	$ 118,726
Total risk-based capital to be well capitalized under prompt corrective action provisions, ratio			0.1000	0.1000
Tier 1 risk-based capital, actual, amount			$ 156,629	$ 128,130
Tier 1 risk-based capital, actual, ratio			0.1206	0.1079
Tier 1 risk-based capital for capital adequacy purposes, amount			$ 77,927	$ 71,236
Tier 1 risk-based capital for capital adequacy purposes, ratio			0.0600	0.0600
Tier 1 risk-based capital for capital adequacy purposes with capital conservation buffer, amount			$ 110,397	$ 100,917
Tier 1 risk-based capital for capital adequacy purposes with capital conservation buffer, ratio			0.0850	0.0850
Tier 1 risk-based capital to be well capitalized under prompt corrective action provisions, amount			$ 103,903	$ 94,981
Tier 1 risk-based capital to be well capitalized under prompt corrective action provisions, ratio			0.0800	0.0800
Tier 1 leverage, actual, amount			$ 156,629	$ 128,130
Tier 1 leverage, actual, ratio			0.1119	0.1009
Tier 1 leverage for capital adequacy purposes, amount			$ 56,005	$ 50,799
Tier 1 leverage for capital adequacy purposes, ratio			0.0400	0.0400
Tier 1 leverage for capital adequacy purposes with capital conservation buffer, amount			$ 56,005	$ 50,799
Tier 1 leverage for capital adequacy purposes with capital conservation buffer, ratio			0.0400	0.0400
Tier 1 leverage to be well capitalized under prompt corrective action provisions, amount			$ 70,007	$ 63,499
Tier 1 leverage to be well capitalized under prompt corrective action provisions, ratio			0.0500	0.0500
Common equity Tier 1, actual, amount			$ 156,629	$ 128,130
Common equity Tier 1, actual ratio			0.1206	0.1079
Common equity Tier 1 for capital adequacy purposes, amount			$ 58,445	$ 53,427
Common equity Tier 1 for capital adequacy purposes, ratio			0.045%	0.045%
Common equity Tier 1 for capital adequacy purposes with capital conservation buffer, amount			$ 90,915	$ 83,108
Common equity Tier 1 for capital adequacy purposes with capital conservation buffer, ratio			7.00%	0.07%
Common equity Tier 1 to be well capitalized under prompt corrective action provisions, amount			$ 84,421	$ 77,172
Common equity Tier 1 to be well capitalized under prompt corrective action provisions, ratio			6.50%	0.065%
Guaranty Bank
Total risk-based capital, actual, amount			$ 267,822	$ 243,106
Total risk-based capital, actual, ratio			0.1268	0.1224
Total risk-based capital for capital adequacy purposes, amount			$ 168,967	$ 158,903
Total risk-based capital for capital adequacy purposes, ratio			0.0800	0.0800
Total risk-based capital for capital adequacy purposes with capital conservation buffer, amount			$ 221,770	$ 208,560
Total risk-based capital for capital adequacy purposes with capital conservation buffer, ratio			0.1050	0.1050
Total risk-based capital to be well capitalized under prompt corrective action provisions, amount			$ 211,209	$ 198,629
Total risk-based capital to be well capitalized under prompt corrective action provisions, ratio			0.1000	0.1000
Tier 1 risk-based capital, actual, amount			$ 244,506	$ 218,647
Tier 1 risk-based capital, actual, ratio			0.1158	0.1101
Tier 1 risk-based capital for capital adequacy purposes, amount			$ 126,726	$ 119,177
Tier 1 risk-based capital for capital adequacy purposes, ratio			0.0600	0.0600
Tier 1 risk-based capital for capital adequacy purposes with capital conservation buffer, amount			$ 179,528	$ 168,834
Tier 1 risk-based capital for capital adequacy purposes with capital conservation buffer, ratio			0.0850	0.0850
Tier 1 risk-based capital to be well capitalized under prompt corrective action provisions, amount			$ 168,967	$ 158,903
Tier 1 risk-based capital to be well capitalized under prompt corrective action provisions, ratio			0.0800	0.0800
Tier 1 leverage, actual, amount			$ 244,506	$ 218,647
Tier 1 leverage, actual, ratio			0.1141	0.1090
Tier 1 leverage for capital adequacy purposes, amount			$ 85,688	$ 80,229
Tier 1 leverage for capital adequacy purposes, ratio			0.0400	0.0400
Tier 1 leverage for capital adequacy purposes with capital conservation buffer, amount			$ 85,688	$ 80,229
Tier 1 leverage for capital adequacy purposes with capital conservation buffer, ratio			0.0400	0.0400
Tier 1 leverage to be well capitalized under prompt corrective action provisions, amount			$ 107,110	$ 100,286
Tier 1 leverage to be well capitalized under prompt corrective action provisions, ratio			0.0500	0.0500
Common equity Tier 1, actual, amount			$ 244,506	$ 218,647
Common equity Tier 1, actual ratio			0.1158	0.1101
Common equity Tier 1 for capital adequacy purposes, amount			$ 95,044	$ 89,383
Common equity Tier 1 for capital adequacy purposes, ratio			0.045%	0.045%
Common equity Tier 1 for capital adequacy purposes with capital conservation buffer, amount			$ 147,847	$ 139,040
Common equity Tier 1 for capital adequacy purposes with capital conservation buffer, ratio			7.00%	0.07%
Common equity Tier 1 to be well capitalized under prompt corrective action provisions, amount			$ 137,286	$ 129,109
Common equity Tier 1 to be well capitalized under prompt corrective action provisions, ratio			0.065%	0.065%