NOTE 4 - SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Securitization (Details) $ in Thousands		1 Months Ended	9 Months Ended	12 Months Ended
	Apr. 30, 2026 USD ($) security	Apr. 30, 2026 USD ($) security	Sep. 30, 2026 USD ($)	Dec. 31, 2025 USD ($) item	Sep. 30, 2025 USD ($)	Aug. 31, 2025 USD ($)
SECURITIZATIONS AND VARIABLE INTEREST ENTITIES
Number of sponsored securitizations completed | item				4
Securities trading, at fair value			$ 116,050	$ 83,857
Net loss on sale			(1,272)
Pledged securities held to maturity, at amortized cost			1,029,597	948,676
Assets			9,795,320	9,498,194	$ 9,568,302
Liabilities			8,643,502	8,385,883
VIE - Not Primary
SECURITIZATIONS AND VARIABLE INTEREST ENTITIES
Assets			116,000	83,900
Liabilities			0	0
Maximum exposure to loss			113,900
Assets pledged as collateral
SECURITIZATIONS AND VARIABLE INTEREST ENTITIES
Pledged securities held to maturity, at amortized cost			167,936	$ 176,632		$ 200,300
Assets pledged as collateral | Class A municipal certificates
SECURITIZATIONS AND VARIABLE INTEREST ENTITIES
Pledged securities held to maturity, at amortized cost						134,200
Assets pledged as collateral | Class B municipal certificates
SECURITIZATIONS AND VARIABLE INTEREST ENTITIES
Pledged securities held to maturity, at amortized cost						$ 66,100
M-series Tax exempt LIHTC loans
SECURITIZATIONS AND VARIABLE INTEREST ENTITIES
Interest rate swaps collateralized by investment securities	$ 281,900	$ 281,900
Net loss on sale	$ (1,300)
Number of securities issued | security	2	2
M-series Tax exempt LIHTC loans | VIE - Not Primary
SECURITIZATIONS AND VARIABLE INTEREST ENTITIES
Assets			33,100
Maximum exposure to loss			$ 28,400
Class B Certificates | Assets pledged as collateral
SECURITIZATIONS AND VARIABLE INTEREST ENTITIES
Percentage of first loss support		10.00%
Amount of first loss support	$ 28,400	$ 28,400
Tax exempt LIHTC loans
SECURITIZATIONS AND VARIABLE INTEREST ENTITIES
Securities trading, at fair value	$ 32,800	$ 32,800