BASIS OF PRESENTATION AND ACCOUNTING POLICIES - Schedule of Error Corrections (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Interest income	$ 355,046	$ 355,146	$ 1,036,462	$ 1,031,921
Interest expense	117,082	141,086	344,846	404,552
Net interest income	237,964	214,060	691,616	627,369
Noninterest income	76,274	69,709	209,208	224,298
Income before income tax expense	137,042	125,885	392,670	349,837
Income tax expense	31,013	26,673	88,872	85,528
Net income	106,029	99,212	303,798	264,309
Total assets	27,099,829	26,399,782	27,099,829	26,399,782	$ 26,262,050
Banking Division
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Interest income	245,322	243,964	717,852	722,943
Interest expense	47,262	71,329	144,078	212,303
Net interest income	198,060	172,635	573,774	510,640
Noninterest income	35,419	26,435	93,418	90,325
Income before income tax expense	97,889	83,604	291,058	227,417
Income tax expense	22,824	17,832	67,645	59,950
Net income	75,065	65,772	223,413	167,467
Total assets	19,510,473	18,983,335	19,510,473	18,983,335
Warehouse Lending Division
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Interest income	18,803	21,677	52,177	57,540
Interest expense	11,329	13,865	31,710	37,408
Net interest income	7,474	7,812	20,467	20,132
Noninterest income	756	1,765	3,203	3,533
Income before income tax expense	7,382	8,871	20,981	19,810
Income tax expense	1,550	1,863	4,406	4,160
Net income	5,832	7,008	16,575	15,650
Total assets	$ 1,105,821	1,001,666	$ 1,105,821	1,001,666
As Reported | Banking Division
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Interest income		255,241		734,220
Interest expense		78,447		219,421
Net interest income		176,794		514,799
Noninterest income		27,800		91,690
Income before income tax expense		89,128		232,941
Income tax expense		18,992		61,110
Net income		70,136		171,831
Total assets		19,387,331		19,387,331
As Reported | Warehouse Lending Division
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Interest income		10,400		46,263
Interest expense		6,747		30,290
Net interest income		3,653		15,973
Noninterest income		400		2,168
Income before income tax expense		3,347		14,286
Income tax expense		703		3,000
Net income		2,644		11,286
Total assets		597,670		597,670
Adjustments | Banking Division
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Interest income		(11,277)		(11,277)
Interest expense		(7,118)		(7,118)
Net interest income		(4,159)		(4,159)
Noninterest income		(1,365)		(1,365)
Income before income tax expense		(5,524)		(5,524)
Income tax expense		(1,160)		(1,160)
Net income		(4,364)		(4,364)
Total assets		(403,996)		(403,996)
Adjustments | Warehouse Lending Division
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Interest income		11,277		11,277
Interest expense		7,118		7,118
Net interest income		4,159		4,159
Noninterest income		1,365		1,365
Income before income tax expense		5,524		5,524
Income tax expense		1,160		1,160
Net income		4,364		4,364
Total assets		$ 403,996		$ 403,996