NOTE 5 - DERIVATIVES AND HEDGING ACTIVITIES - Summary of Hedged Interest Rate Swap and Cap Derivatives (Details) - USD ($) $ in Thousands	12 Months Ended	21 Months Ended
	Dec. 31, 2025	Sep. 30, 2026
Derivative [Line Items]
Derivative Asset	$ 188,409	$ 243,882
Derivative Liabilities	(137,051)	(262,023)
Hedged Derivatives
Derivative [Line Items]
Derivative, Notional Amount	509,310	374,000
Derivative Asset	576	2,434
Derivative Liabilities	(22,499)	(24,761)
Hedged Derivatives | Cash Flow Hedges | Interest rate swaps
Derivative [Line Items]
Derivative Liability, Notional Amount		300,000
Derivative, Notional Amount		114,310
Derivative Assets (Liabilities), net	(444)	1,817
Derivative Liabilities	(19,149)	(23,800)
Hedged Derivatives | Cash Flow Hedges | QCR Holdings Statutory Trust V
Derivative [Line Items]
Derivative Asset, Notional Amount		$ 10,000
Receive Rate		5.56%
Pay Rate		4.54%
Derivative Asset	140	$ 326
Hedged Derivatives | Cash Flow Hedges | Community National Statutory Trust III
Derivative [Line Items]
Derivative Asset, Notional Amount		$ 3,500
Receive Rate		5.91%
Pay Rate		4.75%
Derivative Asset	64	$ 163
Hedged Derivatives | Cash Flow Hedges | Guaranty Bankshares Statutory Trust I
Derivative [Line Items]
Derivative Asset, Notional Amount		$ 4,500
Receive Rate		5.91%
Pay Rate		4.75%
Derivative Asset	50	$ 127
Hedged Derivatives | Cash Flow Hedges | Community National Statutory Trust II
Derivative [Line Items]
Derivative Asset, Notional Amount		$ 3,000
Receive Rate		6.43%
Pay Rate		5.17%
Derivative Asset	43	$ 109
Hedged Derivatives | Cash Flow Hedges | QCR Holdings Statutory Trust II
Derivative [Line Items]
Derivative Asset, Notional Amount		$ 10,000
Receive Rate		7.19%
Pay Rate		5.85%
Derivative Asset	144	$ 370
Hedged Derivatives | Cash Flow Hedges | QCR Holdings Statutory Trust III
Derivative [Line Items]
Derivative Asset, Notional Amount		$ 8,000
Receive Rate		7.19%
Pay Rate		5.85%
Derivative Asset	115	$ 296
Hedged Derivatives | Cash Flow Hedges | Guaranty Statutory Trust II
Derivative [Line Items]
Derivative Asset, Notional Amount		10,310
Derivative Asset	20
Hedged Derivatives | Cash Flow Hedges | QCR Holdings Subordinated Note
Derivative [Line Items]
Derivative Liability, Notional Amount		$ 65,000
Receive Rate		4.02%
Pay Rate		4.02%
Derivative Liabilities	(1,020)	$ 426
Hedged Derivatives | Cash Flow Hedges | Loans, one
Derivative [Line Items]
Derivative Liability, Notional Amount		$ 35,000
Receive Rate		1.40%
Pay Rate		3.75%
Derivative Liabilities	(3,798)	$ (5,143)
Hedged Derivatives | Cash Flow Hedges | Loans, two
Derivative [Line Items]
Derivative Liability, Notional Amount		$ 50,000
Receive Rate		1.40%
Pay Rate		3.75%
Derivative Liabilities	(5,425)	$ (7,347)
Hedged Derivatives | Cash Flow Hedges | Loans, three
Derivative [Line Items]
Derivative Liability, Notional Amount		$ 40,000
Receive Rate		1.40%
Pay Rate		3.75%
Derivative Liabilities	(4,348)	$ (5,885)
Hedged Derivatives | Cash Flow Hedges | Loans, four
Derivative [Line Items]
Derivative Liability, Notional Amount		$ 25,000
Receive Rate		1.30%
Pay Rate		3.62%
Derivative Liabilities	(2,734)	$ (3,659)
Hedged Derivatives | Cash Flow Hedges | Loan five
Derivative [Line Items]
Derivative Liability, Notional Amount		$ 15,000
Receive Rate		1.91%
Pay Rate		3.75%
Derivative Liabilities	(285)	$ (177)
Hedged Derivatives | Cash Flow Hedges | Loan six
Derivative [Line Items]
Derivative Liability, Notional Amount		$ 50,000
Receive Rate		1.91%
Pay Rate		3.75%
Derivative Liabilities	(948)	$ (589)
Hedged Derivatives | Cash Flow Hedges | Loan seven
Derivative [Line Items]
Derivative Liability, Notional Amount		$ 35,000
Receive Rate		1.91%
Pay Rate		3.75%
Derivative Liabilities	(664)	$ (412)
Hedged Derivatives | Cash Flow Hedges | Loan eight
Derivative [Line Items]
Derivative Liability, Notional Amount		$ 50,000
Receive Rate		1.91%
Pay Rate		3.75%
Derivative Liabilities	(947)	$ (588)
Hedged Derivatives | Cash Flow Hedges | Loan nine
Derivative [Line Items]
Derivative Asset, Notional Amount	50,000	50,000
Derivative Liabilities	(1)
Hedged Derivatives | Cash Flow Hedges | Interest rate caps
Derivative [Line Items]
Derivative, Notional Amount	49,310	39,000
Derivative Asset	576	1,817
Derivative Liabilities	(20,169)	(23,800)
Hedged Derivatives | Fair Value Hedges | Interest rate swaps
Derivative [Line Items]
Derivative, Notional Amount	310,000	185,000
Derivative Asset		617
Derivative Liabilities	(2,186)
Derivative Assets (Liabilities), net	(2,186)	617
Hedged Derivatives | Fair Value Hedges | Loan ten
Derivative [Line Items]
Derivative, Notional Amount	$ 25,000
Receive Rate	4.21%
Pay Rate	4.38%
Derivative Liabilities	$ (15)
Hedged Derivatives | Fair Value Hedges | Loan Eleven
Derivative [Line Items]
Derivative, Notional Amount	$ 15,000
Receive Rate	4.21%
Pay Rate	4.38%
Derivative Liabilities	$ (9)
Hedged Derivatives | Fair Value Hedges | Loan Twelve
Derivative [Line Items]
Derivative, Notional Amount	$ 20,000
Receive Rate	4.21%
Pay Rate	4.38%
Derivative Liabilities	$ (12)
Hedged Derivatives | Fair Value Hedges | Loan Thirteen
Derivative [Line Items]
Derivative, Notional Amount		$ 30,000
Receive Rate		3.63%
Pay Rate		4.21%
Derivative Liabilities	(119)
Hedged Derivatives | Fair Value Hedges | Loan fourteen
Derivative [Line Items]
Derivative, Notional Amount		$ 15,000
Receive Rate		3.63%
Pay Rate		4.21%
Derivative Liabilities	(59)
Hedged Derivatives | Fair Value Hedges | Loan fifteen
Derivative [Line Items]
Derivative, Notional Amount		$ 20,000
Receive Rate		3.63%
Pay Rate		4.21%
Derivative Liabilities	(79)
Hedged Derivatives | Fair Value Hedges | Loan sixteen
Derivative [Line Items]
Derivative, Notional Amount		$ 32,500
Receive Rate		3.63%
Pay Rate		4.08%
Derivative Liabilities	(251)
Hedged Derivatives | Fair Value Hedges | Loan seventeen
Derivative [Line Items]
Derivative, Notional Amount		$ 15,000
Receive Rate		3.63%
Pay Rate		4.08%
Derivative Liabilities	(116)
Hedged Derivatives | Fair Value Hedges | Loan Eighteen
Derivative [Line Items]
Derivative, Notional Amount		$ 20,000
Receive Rate		3.63%
Pay Rate		4.08%
Derivative Liabilities	(154)
Hedged Derivatives | Fair Value Hedges | Loan Nineteen
Derivative [Line Items]
Derivative, Notional Amount		$ 32,500
Receive Rate		3.63%
Pay Rate		3.98%
Derivative Asset	(352)
Derivative Liabilities		$ 105
Hedged Derivatives | Fair Value Hedges | Loan Twenty
Derivative [Line Items]
Derivative, Notional Amount		$ 15,000
Receive Rate		3.63%
Pay Rate		3.98%
Derivative Asset	(162)
Derivative Liabilities		$ 49
Hedged Derivatives | Fair Value Hedges | Loan twenty one
Derivative [Line Items]
Derivative, Notional Amount		$ 25,000
Receive Rate		3.63%
Pay Rate		3.98%
Derivative Asset	(271)
Derivative Liabilities		$ 81
Hedged Derivatives | Fair Value Hedges | Loan twenty two
Derivative [Line Items]
Derivative, Notional Amount		$ 30,000
Receive Rate		3.63%
Pay Rate		3.90%
Derivative Asset	(391)
Derivative Liabilities		$ 255
Hedged Derivatives | Fair Value Hedges | Loan twenty three
Derivative [Line Items]
Derivative, Notional Amount		$ 15,000
Receive Rate		3.63%
Pay Rate		3.90%
Derivative Asset	$ (196)
Derivative Liabilities		$ 127