Investment Securities - Continuous Unrealized Loss Position (Details) $ in Thousands	12 Months Ended
Dec. 31, 2023 USD ($) position	Dec. 31, 2022 USD ($) position
Securities
Percentage of AFS investment portfolio	24.00%	95.00%
Percentage of HTM investment portfolio	65.00%	22.00%
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value, Less than 12 Months	$ 63,957	$ 49,545
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value, 12 Months or Longer	199,479	258,411
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	$ 263,436	$ 307,956
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Number of Positions \| position	28	37
Held-to-maturity securities, Continuous Unrealized Loss Position, Fair Value
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value, Total	$ 777,700	$ 247,200
Held-to-maturity Securities, Fair Value, Number of Positions \| position	8	2
Available-for-sale securities, Continuous Unrealized Loss Position, Gross Unrealized Losses
Available-for-sale securities, Continuous Unrealized Loss Position, Gross Unrealized Losses, Less than 12 Months	$ 196	$ 1,493
Available-for-sale securities, Continuous Unrealized Loss Position, Gross Unrealized Losses, 12 Months or Longer	3,121	12,565
Available-for-sale securities, Continuous Unrealized Loss Position, Gross Unrealized Losses, Total	3,317	14,058
Treasury notes
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value, Less than 12 Months	3,052	29,560
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value, 12 Months or Longer	32,080	5,798
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	35,132	35,358
Available-for-sale securities, Continuous Unrealized Loss Position, Gross Unrealized Losses
Available-for-sale securities, Continuous Unrealized Loss Position, Gross Unrealized Losses, Less than 12 Months	6	762
Available-for-sale securities, Continuous Unrealized Loss Position, Gross Unrealized Losses, 12 Months or Longer	332	193
Available-for-sale securities, Continuous Unrealized Loss Position, Gross Unrealized Losses, Total	338	955
Federal agencies
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value, Less than 12 Months	60,541	19,276
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value, 12 Months or Longer	167,213	252,613
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	227,754	271,889
Available-for-sale securities, Continuous Unrealized Loss Position, Gross Unrealized Losses
Available-for-sale securities, Continuous Unrealized Loss Position, Gross Unrealized Losses, Less than 12 Months	189	724
Available-for-sale securities, Continuous Unrealized Loss Position, Gross Unrealized Losses, 12 Months or Longer	2,787	12,372
Available-for-sale securities, Continuous Unrealized Loss Position, Gross Unrealized Losses, Total	2,976	13,096
Mortgage-backed - Agency
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value, Less than 12 Months	364	709
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value, 12 Months or Longer	186
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	550	709
Available-for-sale securities, Continuous Unrealized Loss Position, Gross Unrealized Losses
Available-for-sale securities, Continuous Unrealized Loss Position, Gross Unrealized Losses, Less than 12 Months	1	7
Available-for-sale securities, Continuous Unrealized Loss Position, Gross Unrealized Losses, 12 Months or Longer	2
Available-for-sale securities, Continuous Unrealized Loss Position, Gross Unrealized Losses, Total	$ 3	$ 7

Number of investments in debt securities measured at amortized cost (held-to-maturity).

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