Investment Securities - Investment Securities Available-for-sale (Details) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 917,899	$ 964,389
Gross Unrealized Gains	2,286	867
Gross Unrealized Losses	53,501	70,222
Estimated Fair Value	866,684	895,034
GSE debentures
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	191,885	195,099
Gross Unrealized Gains	417	225
Gross Unrealized Losses	14,617	19,030
Estimated Fair Value	177,685	176,294
GSE CMOs
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	60,498	62,567
Gross Unrealized Gains	35	4
Gross Unrealized Losses	6,466	7,028
Estimated Fair Value	54,067	55,543
GSE MBSs
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	155,443	166,843
Gross Unrealized Gains	92	63
Gross Unrealized Losses	14,348	18,621
Estimated Fair Value	141,187	148,285
Municipal obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	19,229	20,526
Gross Unrealized Gains	27	19
Gross Unrealized Losses	310	291
Estimated Fair Value	18,946	20,254
Corporate debt obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	12,205	12,140
Gross Unrealized Gains	308	225
Gross Unrealized Losses	287	78
Estimated Fair Value	12,226	12,287
U.S. Treasury bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	478,139	506,714
Gross Unrealized Gains	1,407	331
Gross Unrealized Losses	17,473	25,173
Estimated Fair Value	462,073	481,872
Foreign government obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	500	500
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	1
Estimated Fair Value	$ 500	$ 499

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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