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Investment Securities - Amortized Cost to Approximate Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Available for sale securities:
Amortized Cost	$ 1,116,954	$ 337,387
Gross Unrealized Gains	50	8
Gross Unrealized Losses	3,317	14,058
Fair Value	1,113,687	323,337
Accrued interest on securities available for sale	6,700	500
Accrued interest on securities held to maturity	5,800	4,300
Held to maturity securities:
Amortized Cost	1,204,217	1,119,078
Gross Unrealized Gains	973	12
Gross Unrealized Losses	1,655	124
Fair Value	1,203,535	1,118,966
Treasury notes
Available for sale securities:
Amortized Cost	129,261	37,234
Gross Unrealized Gains	45	1
Gross Unrealized Losses	338	955
Fair Value	128,968	36,280
Federal agencies
Available for sale securities:
Amortized Cost	250,731	284,986
Gross Unrealized Losses	2,976	13,096
Fair Value	247,755	271,890
Mortgage-backed - Agency
Available for sale securities:
Amortized Cost		15,167
Gross Unrealized Gains		7
Gross Unrealized Losses		7
Fair Value		15,167
Held to maturity securities:
Amortized Cost	12,016
Gross Unrealized Losses	822
Fair Value	11,194
Mortgage-backed - Government Agency ("Agency")
Available for sale securities:
Amortized Cost	14,465
Gross Unrealized Gains	5
Gross Unrealized Losses	3
Fair Value	14,467
Mortgage-backed - Agency - fair value option
Available for sale securities:
Amortized Cost	236,997
Fair Value	236,997
Mortgage-backed - Non-Agency multi-family
Held to maturity securities:
Amortized Cost	719,662	871,772
Gross Unrealized Gains		12
Gross Unrealized Losses	415
Fair Value	719,247	871,784
Mortgage-backed - Non-Agency residential
Available for sale securities:
Amortized Cost	485,500
Fair Value	485,500
Held to maturity securities:
Amortized Cost	472,539	247,306
Gross Unrealized Gains	973
Gross Unrealized Losses	418	124
Fair Value	$ 473,094	$ 247,182

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