Note 4 - Loans - Loan Held for Investment by Loan Portfolio Segments, Internal Risk Ratings and Vintage Year (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Originated current year	$ 3,411,331	$ 2,545,564
Originated prior year	2,146,605	3,349,730
Originated two years prior	2,947,859	3,168,851
Originated three years prior	2,725,330	2,593,759
Originated four years prior	2,297,334	1,364,973
Originated years prior	4,255,068	4,069,831
Revolving	2,323,975	2,248,231
Converted to Term	24,797	24,475
Loans	20,132,299	19,365,414
Doubtful	20,132,299	19,365,414
Current year, write offs	0	188
Prior year, write offs	249	1,586
Two years prior, write offs	715	3,166
Three years prior, write offs	2,752	9,009
Four years prior, write offs	5,399	553
Years prior, write offs	16,135	4,237
Revolving, write offs	12,487	12,733
Converted to term, write offs	0	0
Loans, write offs	37,737	31,472
Commercial Portfolio Segment [Member]
Originated current year	400,479	402,743
Originated prior year	226,310	259,797
Originated two years prior	237,136	216,034
Originated three years prior	160,611	211,728
Originated four years prior	165,594	58,833
Originated years prior	100,473	102,119
Revolving	1,881,850	1,835,445
Converted to Term	7,300	8,026
Loans	3,179,753	3,094,725
Doubtful	3,179,753	3,094,725
Current year, write offs	0	188
Prior year, write offs	175	1,586
Two years prior, write offs	715	3,151
Three years prior, write offs	2,752	8,950
Four years prior, write offs	4,469	257
Years prior, write offs	12,503	64
Revolving, write offs	12,487	12,730
Converted to term, write offs	0	0
Loans, write offs	33,101	26,926
Commercial Portfolio Segment [Member] | Pass [Member]
Originated current year	384,065	400,836
Originated prior year	190,685	237,303
Originated two years prior	220,174	203,190
Originated three years prior	154,865	201,837
Originated four years prior	157,979	27,359
Originated years prior	85,858	90,724
Revolving	1,702,322	1,675,260
Converted to Term	6,269	7,804
Loans	2,902,217	2,844,313
Doubtful	2,902,217	2,844,313
Commercial Portfolio Segment [Member] | Special Mention [Member]
Originated current year	0	0
Originated prior year	33,459	17,424
Originated two years prior	0	740
Originated three years prior	1,462	0
Originated four years prior	5,000	9,117
Originated years prior	3,875	5,139
Revolving	117,738	92,632
Converted to Term	0	0
Loans	161,534	125,052
Doubtful	161,534	125,052
Commercial Portfolio Segment [Member] | Substandard [Member]
Originated current year	16,414	50
Originated prior year	2,166	5,070
Originated two years prior	16,962	12,104
Originated three years prior	2,479	6,773
Originated four years prior	2,615	22,357
Originated years prior	10,443	6,256
Revolving	61,790	67,553
Converted to Term	1,031	222
Loans	113,900	120,385
Doubtful	113,900	120,385
Commercial Portfolio Segment [Member] | Doubtful [Member]
Originated current year	0	1,857
Originated prior year	0	0
Originated two years prior	0	0
Originated three years prior	1,805	3,118
Originated four years prior	0	0
Originated years prior	297	0
Revolving	0	0
Converted to Term	0	0
Loans	2,102	4,975
Doubtful	2,102	4,975
Real Estate Construction Portfolio Segment [Member]
Originated current year	86,893	22,562
Originated prior year	69,113	60,065
Originated two years prior	47,036	126,200
Originated three years prior	68,635	93,115
Originated four years prior	56,343	16,858
Originated years prior	6,636	0
Revolving	1,298	0
Converted to Term	0	0
Loans	335,954	318,800
Doubtful	335,954	318,800
Current year, write offs	0	0
Prior year, write offs	0	0
Two years prior, write offs	0	0
Three years prior, write offs	0	0
Four years prior, write offs	0	0
Years prior, write offs	0	0
Revolving, write offs	0	0
Converted to term, write offs	0	0
Loans, write offs	0	0
Real Estate Construction Portfolio Segment [Member] | Pass [Member]
Originated current year	86,893	22,562
Originated prior year	69,113	55,835
Originated two years prior	37,801	126,200
Originated three years prior	68,635	57,546
Originated four years prior	30,283	3,021
Originated years prior	0	0
Revolving	1,298	0
Converted to Term	0	0
Loans	294,023	265,164
Doubtful	294,023	265,164
Real Estate Construction Portfolio Segment [Member] | Special Mention [Member]
Originated current year	0	0
Originated prior year	0	0
Originated two years prior	9,235	0
Originated three years prior	0	35,569
Originated four years prior	0	13,837
Originated years prior	0	0
Revolving	0	0
Converted to Term	0	0
Loans	9,235	49,406
Doubtful	9,235	49,406
Real Estate Construction Portfolio Segment [Member] | Substandard [Member]
Originated current year	0	0
Originated prior year	0	4,230
Originated two years prior	0	0
Originated three years prior	0	0
Originated four years prior	26,060	0
Originated years prior	6,636	0
Revolving	0	0
Converted to Term	0	0
Loans	32,696	4,230
Doubtful	32,696	4,230
Commercial Real Estate Portfolio Segment [Member]
Originated current year	1,941,874	1,472,030
Originated prior year	1,360,416	2,006,936
Originated two years prior	1,758,888	1,807,297
Originated three years prior	1,582,709	1,502,515
Originated four years prior	1,382,164	832,435
Originated years prior	2,298,683	2,206,768
Revolving	230,077	198,485
Converted to Term	1,208	0
Loans	10,556,019	10,026,466
Doubtful	10,556,019	10,026,466
Current year, write offs	0	0
Prior year, write offs	0	0
Two years prior, write offs	0	0
Three years prior, write offs	0	0
Four years prior, write offs	930	296
Years prior, write offs	3,632	4,173
Revolving, write offs	0	0
Converted to term, write offs	0	0
Loans, write offs	4,562	4,469
Commercial Real Estate Portfolio Segment [Member] | Pass [Member]
Originated current year	1,909,540	1,463,225
Originated prior year	1,286,856	1,987,280
Originated two years prior	1,673,226	1,724,563
Originated three years prior	1,442,872	1,428,124
Originated four years prior	1,290,175	800,645
Originated years prior	2,184,774	2,108,143
Revolving	206,139	180,394
Converted to Term	0	0
Loans	9,993,582	9,692,374
Doubtful	9,993,582	9,692,374
Commercial Real Estate Portfolio Segment [Member] | Special Mention [Member]
Originated current year	29,745	8,805
Originated prior year	58,491	8,292
Originated two years prior	74,142	28,465
Originated three years prior	113,065	16,462
Originated four years prior	32,074	24,844
Originated years prior	33,062	19,888
Revolving	22,214	9,939
Converted to Term	0	0
Loans	362,793	116,695
Doubtful	362,793	116,695
Commercial Real Estate Portfolio Segment [Member] | Substandard [Member]
Originated current year	2,589	0
Originated prior year	15,069	11,364
Originated two years prior	11,520	54,269
Originated three years prior	26,772	57,929
Originated four years prior	59,915	6,946
Originated years prior	63,004	78,737
Revolving	1,724	8,152
Converted to Term	1,208	0
Loans	181,801	217,397
Doubtful	181,801	217,397
Commercial Real Estate Portfolio Segment [Member] | Doubtful [Member]
Originated current year	0
Originated prior year	0
Originated two years prior	0
Originated three years prior	0
Originated four years prior	0
Originated years prior	17,843
Revolving	0
Converted to Term	0
Loans	17,843
Doubtful	17,843
Residential Portfolio Segment [Member]
Originated current year	980,450	642,965
Originated prior year	490,658	1,022,932
Originated two years prior	904,799	1,019,204
Originated three years prior	913,304	786,401
Originated four years prior	693,233	456,847
Originated years prior	1,849,276	1,760,944
Revolving	0	0
Converted to Term	0	0
Loans	5,831,720	5,689,293
Doubtful	5,831,720	5,689,293
Current year, write offs	0	0
Prior year, write offs	74	0
Two years prior, write offs	0	0
Three years prior, write offs	0	59
Four years prior, write offs	0	0
Years prior, write offs	0	0
Revolving, write offs	0	0
Converted to term, write offs	0	0
Loans, write offs	74	59
Residential Portfolio Segment [Member] | Pass [Member]
Originated current year	980,403	642,568
Originated prior year	488,518	1,020,419
Originated two years prior	899,547	1,014,842
Originated three years prior	905,719	781,218
Originated four years prior	688,469	452,623
Originated years prior	1,826,904	1,745,923
Revolving	0	0
Converted to Term	0	0
Loans	5,789,560	5,657,593
Doubtful	5,789,560	5,657,593
Residential Portfolio Segment [Member] | Special Mention [Member]
Originated current year	0	0
Originated prior year	0	0
Originated two years prior	0	0
Originated three years prior	0	0
Originated four years prior	0	33
Originated years prior	1,571	1,585
Revolving	0	0
Converted to Term	0	0
Loans	1,571	1,618
Doubtful	1,571	1,618
Residential Portfolio Segment [Member] | Substandard [Member]
Originated current year	47	397
Originated prior year	2,140	2,513
Originated two years prior	5,252	4,362
Originated three years prior	7,585	5,183
Originated four years prior	4,764	4,191
Originated years prior	20,801	13,436
Revolving	0	0
Converted to Term	0	0
Loans	40,589	30,082
Doubtful	40,589	30,082
Equity Lines Portfolio Segment [Member]
Originated current year	0	0
Originated prior year	0	0
Originated two years prior	0	72
Originated three years prior	0	0
Originated four years prior	0	0
Originated years prior	0	0
Revolving	210,750	214,301
Converted to Term	16,289	16,449
Loans	227,039	230,822
Doubtful	227,039	230,822
Current year, write offs	0	0
Prior year, write offs	0	0
Two years prior, write offs	0	0
Three years prior, write offs	0	0
Four years prior, write offs	0	0
Years prior, write offs	0	0
Revolving, write offs	0	3
Converted to term, write offs	0	0
Loans, write offs	0	3
Equity Lines Portfolio Segment [Member] | Pass [Member]
Originated current year	0	0
Originated prior year	0	0
Originated two years prior	0	72
Originated three years prior	0	0
Originated four years prior	0	0
Originated years prior	0	0
Revolving	209,256	211,374
Converted to Term	15,853	16,277
Loans	225,109	227,723
Doubtful	225,109	227,723
Equity Lines Portfolio Segment [Member] | Special Mention [Member]
Originated current year	0	0
Originated prior year	0	0
Originated two years prior	0	0
Originated three years prior	0	0
Originated four years prior	0	0
Originated years prior	0	0
Revolving	0	0
Converted to Term	0	11
Loans	0	11
Doubtful	0	11
Equity Lines Portfolio Segment [Member] | Substandard [Member]
Originated current year	0	0
Originated prior year	0	0
Originated two years prior	0	0
Originated three years prior	0	0
Originated four years prior	0	0
Originated years prior	0	0
Revolving	1,494	2,927
Converted to Term	436	161
Loans	1,930	3,088
Doubtful	1,930	3,088
Installment and Other Loans [Member ]
Originated current year	1,635	5,264
Originated prior year	108	0
Originated two years prior	0	44
Originated three years prior	71	0
Originated four years prior	0	0
Originated years prior	0	0
Revolving	0	0
Converted to Term	0	0
Loans	1,814	5,308
Doubtful	1,814	5,308
Current year, write offs	0	0
Prior year, write offs	0	0
Two years prior, write offs	0	15
Three years prior, write offs	0	0
Four years prior, write offs	0	0
Years prior, write offs	0	0
Revolving, write offs	0	0
Converted to term, write offs	0	0
Loans, write offs	0	15
Installment and Other Loans [Member ] | Pass [Member]
Originated current year	1,635	5,264
Originated prior year	108	0
Originated two years prior	0	44
Originated three years prior	71	0
Originated four years prior	0	0
Originated years prior	0	0
Revolving	0	0
Converted to Term	0	0
Loans	1,814	5,308
Doubtful	$ 1,814	$ 5,308