MORTGAGE SERVICING RIGHTS - Fair Value Disclosures (Detail) - MSRs - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
MORTGAGE SERVICING RIGHTS
Fair value of the MSRs	$ 1,400.0	$ 1,400.0
Sensitivity Analysis of Fair Value, example 1, impact of percent adverse change in discount rate, percent	1.00%
Decrease in fair value as a result of 100 basis point increase in discount rate	$ 39.4
Sensitivity Analysis of Fair Value, example 2, impact of percent adverse change in discount rate, percent	2.00%
Decrease in fair value as a result of 200 basis point increase in discount rate	$ 76.1
Sensitivity Analysis of Fair Value, example 1, impact of percent adverse change in placement fee rate, percent	0.50%
Decrease in fair value as a result of 50 basis point decrease in placement fee rate	$ 49.7
Sensitivity Analysis of Fair Value, example 2, impact of percent adverse change in placement fee rate, percent	1.00%
Decrease in fair value as a result of 100 basis point decrease in placement fee rate	$ 99.5