NOTE 9 - BUSINESS SEGMENT INFORMATION - Intercompany Eliminations (Details) - Intercompany Eliminations - Commercial Banking - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Segment Reporting Information [Line Items]
Equity in net income of subsidiary bank	$ 40,286	$ 30,457
Investment in subsidiary bank	1,378,377	1,291,433
QCBT
Segment Reporting Information [Line Items]
Equity in net income of subsidiary bank	9,673	8,543
Investment in subsidiary bank	307,860	289,980
CRBT
Segment Reporting Information [Line Items]
Equity in net income of subsidiary bank	17,429	13,605
Investment in subsidiary bank	476,302	438,716
CSB
Segment Reporting Information [Line Items]
Equity in net income of subsidiary bank	5,755	4,137
Investment in subsidiary bank	200,462	177,664
GB
Segment Reporting Information [Line Items]
Equity in net income of subsidiary bank	7,429	4,172
Investment in subsidiary bank	$ 393,753	$ 385,073