EQUITY - Narrative (Details)			1 Months Ended	3 Months Ended		12 Months Ended			132 Months Ended
	Aug. 25, 2025 USD ($)	Jul. 18, 2024	Aug. 31, 2025 USD ($) $ / shares shares	Dec. 31, 2025 USD ($) $ / shares shares	Sep. 30, 2024 USD ($)	Dec. 31, 2025 USD ($) classOfCommonStockOutstanding $ / shares	Dec. 31, 2024 USD ($) $ / shares	Dec. 31, 2023 USD ($) $ / shares	Dec. 31, 2025 USD ($) $ / shares shares	Aug. 05, 2025 USD ($)	Aug. 04, 2025 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of classes of common stock outstanding | classOfCommonStockOutstanding						3
Quarterly dividend on all classes of common stock (in dollars per share) | $ / shares						$ 1.50	$ 1.40	$ 1.10
Share repurchase program, authorized amount										$ 50,000,000.0	$ 9,800,000
Remaining authorized amount for repurchase				$ 37,100,000		$ 37,100,000			$ 37,100,000
Share expiration period						10 years
Compensation expense						$ 8,300,000	$ 8,100,000	$ 6,800,000
Decrease in additional paid-in capital						5,200,000	5,400,000	$ 3,100,000
Capital required for capital adequacy				1,000,000,000.0		1,000,000,000.0	917,600,000		1,000,000,000.0
Capital				1,700,000,000		1,700,000,000	1,500,000,000		1,700,000,000
Excess capital				$ 677,700,000		$ 677,700,000	$ 583,500,000		$ 677,700,000
Class C non-voting common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Repurchase of class C common stock (in shares) | shares				78,481					751,000
Repurchase of Class C Common Stock				$ 12,900,000					$ 32,700,000
6.500% Non-Cumulative Preferred Stock, Series H
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Sale of stock, number of shares issued | shares			4,000,000.0
Preferred stock, dividend rate	6.50%		6.50%
Preferred stock, par value (in dollars per share) | $ / shares			$ 25.00	$ 25		$ 25	$ 25		$ 25
Payments of stock issuance costs	$ 3,156,010		$ 3,100,000
Series C
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred stock, dividend rate		6.00%
Loss on retirement of preferred stock					$ 1,600,000