GOVERNMENT AND GOVERNMENT-BACKED SECURITIES - Summary of Real Estate and Other Securities for Held to Maturity (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2025 USD ($) security	Dec. 31, 2024 USD ($)
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Outstanding Face Amount	$ 17,544,124	$ 15,878,274
Weighted Average Life (Years)	4 years
Residential Mortgage Backed Securities, Held To Maturity, Treasury
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Outstanding Face Amount	$ 25,000
Amortized Cost / Carrying Value	24,790	$ 24,770
Fair Value (A)	24,788
Unrecognized Gains /(Losses)	$ (2)
Number of Securities | security	1
Weighted Average Yield	3.90%
Weighted Average Life (Years)	2 months 12 days