Investment Securities - Amortized Cost to Approximate Fair Value (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2022	Sep. 30, 2022	Dec. 31, 2021
Available for sale securities:
Amortized Cost	$ 337,675	$ 337,675	$ 312,590
Gross Unrealized Gains	10	10	77
Gross Unrealized Losses	15,616	15,616	2,038
Fair Value	322,069	322,069	310,629
Securities sold	0	0
Other security was fully amortized	0	0
Accrued interest on available for sale securities	600	600	400
Accrued interest on held to maturity securities	2,300	2,300	0
Held to maturity securities:
Amortized Cost	1,005,487	1,005,487
Fair Value	1,005,487	1,005,487	0
Treasury notes
Available for sale securities:
Amortized Cost	37,288	37,288	8,232
Gross Unrealized Gains			4
Gross Unrealized Losses	976	976	27
Fair Value	36,312	36,312	8,209
Federal agencies
Available for sale securities:
Amortized Cost	284,982	284,982	264,970
Gross Unrealized Losses	14,629	14,629	1,675
Fair Value	270,353	270,353	263,295
Municipals.
Available for sale securities:
Amortized Cost			4,300
Fair Value			4,300
Mortgage-backed - Government-sponsored entity (GSE)
Available for sale securities:
Amortized Cost	15,405	15,405	18,664
Gross Unrealized Gains	10	10	32
Gross Unrealized Losses	11	11	336
Fair Value	15,404	15,404	18,360
Mortgage-backed - Non-GSE multi-family
Available for sale securities:
Amortized Cost			16,424
Gross Unrealized Gains			41
Fair Value			$ 16,465
Held to maturity securities:
Amortized Cost	1,005,487	1,005,487
Fair Value	$ 1,005,487	$ 1,005,487

The amount accrued interest on available for sale securities.

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The amount of accrued interest on held to maturity securities.

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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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Amount, before tax, of unrealized loss 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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Amortized cost excluding accrued interest, after allowance for credit loss, of 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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Amount of realized gain 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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Amount excluding accrued interest, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity).

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Fair value of investment in debt security measured at amortized cost (held-to-maturity).

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