GOODWILL AND OTHER INTANGIBLE ASSETS - Schedule of Goodwill (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Roll Forward of Gross Goodwill
Beginning balance	$ 963,710,000	$ 963,710,000
Ending gross goodwill balance	963,710,000	963,710,000	$ 963,710,000
Roll Forward of Accumulated Goodwill Impairment
Beginning balance	95,000,000	62,000,000
Goodwill impairment	0	33,000,000	62,000,000
Ending accumulated goodwill impairment	95,000,000	95,000,000	62,000,000
Goodwill	868,710,000	868,710,000
Capital Markets
Roll Forward of Gross Goodwill
Beginning balance	524,189,000	524,189,000
Ending gross goodwill balance	524,189,000	524,189,000	524,189,000
Roll Forward of Accumulated Goodwill Impairment
Beginning balance	95,000,000	62,000,000
Goodwill impairment		33,000,000
Ending accumulated goodwill impairment	95,000,000	95,000,000	62,000,000
Goodwill	429,189,000	429,189,000
Servicing and Asset Management
Roll Forward of Gross Goodwill
Beginning balance	439,521,000	439,521,000
Additions from acquisitions	0	0
Measurement-period and other adjustments	0	0
Ending gross goodwill balance	439,521,000	439,521,000	439,521,000
Roll Forward of Accumulated Goodwill Impairment
Beginning balance	0	0
Goodwill impairment	0	0
Ending accumulated goodwill impairment	0	0	$ 0
Goodwill	439,521,000	439,521,000
Corporate
Roll Forward of Accumulated Goodwill Impairment
Goodwill	$ 0	$ 0