Note 3 - Debt Securities Available for Sale and Held to Maturity - Gross Unrealized Losses, Investment Securities Portfolio (Details) $ in Thousands |
Mar. 31, 2026
USD ($)
|
Dec. 31, 2025
USD ($)
|
| Available for sale securities, less than 12 months, number of investment positions |
120
|
62
|
| Held to Maturity securities, less than 12 months, number of investment positions |
25
|
0
|
| Available for sale securities, less than 12 months, fair value |
$ 933,964
|
$ 474,949
|
| Held to Maturity securities, less than 12 months, fair value |
227,213
|
0
|
| Available for sale securities, less than 12 months, unrealized loss |
(11,674)
|
(3,636)
|
| Held to Maturity securities, less than 12 months, unrealized loss |
$ (917)
|
$ 0
|
| Available for sale securities, 12 months or longer, number of investment positions |
276
|
288
|
| Held to Maturity securities, 12 months or longer, number of investment positions |
87
|
99
|
| Available for sale securities, 12 months or longer, fair value |
$ 2,239,865
|
$ 2,349,226
|
| Held to Maturity securities, 12 months or longer, fair value |
402,789
|
416,031
|
| Available for sale securities, 12 months or longer, unrealized loss |
(141,894)
|
(127,837)
|
| Held to Maturity securities, 12 months or longer, unrealized loss |
$ (15,071)
|
$ (10,276)
|
| Available for sale securities, total, number of investment positions |
396
|
350
|
| Held to Maturity securities, total, number of investment positions |
112
|
99
|
| Available for sale securities, total, fair value |
$ 3,173,829
|
$ 2,824,175
|
| Held to Maturity securities, total, fair value |
630,002
|
416,031
|
| Available for sale securities, total, unrealized loss |
(153,568)
|
(131,473)
|
| Held to Maturity securities, total, unrealized loss |
$ (15,988)
|
$ (10,276)
|
| Agency Residential MBS [Member] |
|
|
| Available for sale securities, less than 12 months, number of investment positions |
4
|
2
|
| Held to Maturity securities, less than 12 months, number of investment positions |
0
|
0
|
| Available for sale securities, less than 12 months, fair value |
$ 13,297
|
$ 10,541
|
| Held to Maturity securities, less than 12 months, fair value |
0
|
0
|
| Available for sale securities, less than 12 months, unrealized loss |
(204)
|
(147)
|
| Held to Maturity securities, less than 12 months, unrealized loss |
$ 0
|
$ 0
|
| Available for sale securities, 12 months or longer, number of investment positions |
104
|
107
|
| Held to Maturity securities, 12 months or longer, number of investment positions |
54
|
59
|
| Available for sale securities, 12 months or longer, fair value |
$ 163,509
|
$ 173,186
|
| Held to Maturity securities, 12 months or longer, fair value |
38,020
|
40,523
|
| Available for sale securities, 12 months or longer, unrealized loss |
(10,484)
|
(9,909)
|
| Held to Maturity securities, 12 months or longer, unrealized loss |
$ (2,311)
|
$ (2,231)
|
| Available for sale securities, total, number of investment positions |
108
|
109
|
| Held to Maturity securities, total, number of investment positions |
54
|
59
|
| Available for sale securities, total, fair value |
$ 176,806
|
$ 183,727
|
| Held to Maturity securities, total, fair value |
38,020
|
40,523
|
| Available for sale securities, total, unrealized loss |
(10,688)
|
(10,056)
|
| Held to Maturity securities, total, unrealized loss |
$ (2,311)
|
$ (2,231)
|
| US States and Political Subdivisions Debt Securities [Member] |
|
|
| Available for sale securities, less than 12 months, number of investment positions |
2
|
2
|
| Held to Maturity securities, less than 12 months, number of investment positions |
1
|
0
|
| Available for sale securities, less than 12 months, fair value |
$ 4,201
|
$ 3,382
|
| Held to Maturity securities, less than 12 months, fair value |
624
|
0
|
| Available for sale securities, less than 12 months, unrealized loss |
(23)
|
(1)
|
| Held to Maturity securities, less than 12 months, unrealized loss |
$ (1)
|
$ 0
|
| Available for sale securities, 12 months or longer, number of investment positions |
28
|
28
|
| Held to Maturity securities, 12 months or longer, number of investment positions |
10
|
17
|
| Available for sale securities, 12 months or longer, fair value |
$ 36,135
|
$ 37,520
|
| Held to Maturity securities, 12 months or longer, fair value |
9,344
|
16,087
|
| Available for sale securities, 12 months or longer, unrealized loss |
(679)
|
(542)
|
| Held to Maturity securities, 12 months or longer, unrealized loss |
$ (15)
|
$ (36)
|
| Available for sale securities, total, number of investment positions |
30
|
30
|
| Held to Maturity securities, total, number of investment positions |
11
|
17
|
| Available for sale securities, total, fair value |
$ 40,336
|
$ 40,902
|
| Held to Maturity securities, total, fair value |
9,968
|
16,087
|
| Available for sale securities, total, unrealized loss |
(702)
|
(543)
|
| Held to Maturity securities, total, unrealized loss |
$ (16)
|
$ (36)
|
| Agency Commercial MBS [Member] |
|
|
| Available for sale securities, less than 12 months, number of investment positions |
99
|
56
|
| Available for sale securities, less than 12 months, fair value |
$ 809,211
|
$ 438,102
|
| Available for sale securities, less than 12 months, unrealized loss |
$ (10,564)
|
$ (3,411)
|
| Available for sale securities, 12 months or longer, number of investment positions |
0
|
0
|
| Available for sale securities, 12 months or longer, fair value |
$ 0
|
$ 0
|
| Available for sale securities, 12 months or longer, unrealized loss |
$ 0
|
$ 0
|
| Available for sale securities, total, number of investment positions |
99
|
56
|
| Available for sale securities, total, fair value |
$ 809,211
|
$ 438,102
|
| Available for sale securities, total, unrealized loss |
$ (10,564)
|
$ (3,411)
|
| Corporate Debt Securities [Member] |
|
|
| Available for sale securities, less than 12 months, number of investment positions |
12
|
0
|
| Held to Maturity securities, less than 12 months, number of investment positions |
24
|
0
|
| Available for sale securities, less than 12 months, fair value |
$ 78,980
|
$ 0
|
| Held to Maturity securities, less than 12 months, fair value |
226,589
|
0
|
| Available for sale securities, less than 12 months, unrealized loss |
(777)
|
0
|
| Held to Maturity securities, less than 12 months, unrealized loss |
$ (916)
|
$ 0
|
| Available for sale securities, 12 months or longer, number of investment positions |
124
|
129
|
| Held to Maturity securities, 12 months or longer, number of investment positions |
23
|
23
|
| Available for sale securities, 12 months or longer, fair value |
$ 1,746,543
|
$ 1,804,080
|
| Held to Maturity securities, 12 months or longer, fair value |
355,425
|
359,421
|
| Available for sale securities, 12 months or longer, unrealized loss |
(121,339)
|
(109,473)
|
| Held to Maturity securities, 12 months or longer, unrealized loss |
$ (12,745)
|
$ (8,009)
|
| Available for sale securities, total, number of investment positions |
136
|
129
|
| Held to Maturity securities, total, number of investment positions |
47
|
23
|
| Available for sale securities, total, fair value |
$ 1,825,523
|
$ 1,804,080
|
| Held to Maturity securities, total, fair value |
582,014
|
359,421
|
| Available for sale securities, total, unrealized loss |
(122,116)
|
(109,473)
|
| Held to Maturity securities, total, unrealized loss |
$ (13,661)
|
$ (8,009)
|
| US Government Agencies Debt Securities [Member] |
|
|
| Available for sale securities, less than 12 months, number of investment positions |
1
|
0
|
| Available for sale securities, less than 12 months, fair value |
$ 5,351
|
$ 0
|
| Available for sale securities, less than 12 months, unrealized loss |
$ (30)
|
$ 0
|
| Available for sale securities, 12 months or longer, number of investment positions |
18
|
19
|
| Available for sale securities, 12 months or longer, fair value |
$ 282,938
|
$ 284,747
|
| Available for sale securities, 12 months or longer, unrealized loss |
$ (9,177)
|
$ (6,739)
|
| Available for sale securities, total, number of investment positions |
19
|
19
|
| Available for sale securities, total, fair value |
$ 288,289
|
$ 284,747
|
| Available for sale securities, total, unrealized loss |
$ (9,207)
|
$ (6,739)
|
| Collateralized Debt Obligations [Member] |
|
|
| Available for sale securities, less than 12 months, number of investment positions |
2
|
2
|
| Available for sale securities, less than 12 months, fair value |
$ 22,924
|
$ 22,924
|
| Available for sale securities, less than 12 months, unrealized loss |
$ (76)
|
$ (77)
|
| Available for sale securities, 12 months or longer, number of investment positions |
2
|
5
|
| Available for sale securities, 12 months or longer, fair value |
$ 10,740
|
$ 49,693
|
| Available for sale securities, 12 months or longer, unrealized loss |
$ (215)
|
$ (1,174)
|
| Available for sale securities, total, number of investment positions |
4
|
7
|
| Available for sale securities, total, fair value |
$ 33,664
|
$ 72,617
|
| Available for sale securities, total, unrealized loss |
$ (291)
|
$ (1,251)
|